[PATCH] kselftest/arm64: Validate SVCR in streaming SVE stress test

[Mark Brown]

In the ZA and ZT test programs we explicitly validate that PSTATE.ZA is as
expected on each loop but we do not do the equivalent for our streaming
SVE test, add a check that we are still in streaming mode on every loop
in case that goes wrong.

Signed-off-by: Mark Brown <broo...@kernel.org>
---
 tools/testing/selftests/arm64/fp/sve-test.S | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tools/testing/selftests/arm64/fp/sve-test.S 
b/tools/testing/selftests/arm64/fp/sve-test.S
index 4328895dfc87..547d077e3517 100644
--- a/tools/testing/selftests/arm64/fp/sve-test.S
+++ b/tools/testing/selftests/arm64/fp/sve-test.S
@@ -473,6 +473,13 @@ function _start
 //     mov     x8, #__NR_sched_yield   // Encourage preemption
 //     svc     #0
 
+#ifdef SSVE
+       mrs     x0, S3_3_C4_C2_2        // SVCR should have ZA=0,SM=1
+       and     x1, x0, #3
+       cmp     x1, #1
+       b.ne    svcr_barf
+#endif
+
        mov     x21, #0
 0:     mov     x0, x21
        bl      check_zreg
@@ -553,3 +560,15 @@ function vl_barf
        mov     x1, #1
        svc     #0
 endfunction
+
+function svcr_barf
+       mov     x10, x0
+
+       puts    "Bad SVCR: "
+       mov     x0, x10
+       bl      putdecn
+
+       mov     x8, #__NR_exit
+       mov     x1, #1
+       svc     #0
+endfunction

---
base-commit: ce9ecca0238b140b88f43859b211c9fdfd8e5b70
change-id: 20230921-arm64-ssve-validate-svcr-316852554fc8

Best regards,
-- 
Mark Brown <broo...@kernel.org>