kselftest/arm64: Fix enumeration of systems without 128 bit SME for SSVE+ZA

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 in the newly
added ssve_za_regs test.

Fixes: bc69da5ff087 ("kselftest/arm64: Verify simultaneous SSVE and ZA context generation")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230131-arm64-kselftest-sig-sme-no-128-v1-2-d47c13dc8e1e@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c
index 954a21f6121a273f86f02fed080ab2d3e937cec3..1f62621794d50f4d5fcedc2e7a6d61a6b3b7eb27 100644 (file)
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_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);