kselftest/arm64: Validate SVCR in streaming SVE stress test

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 <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230922-arm64-ssve-validate-svcr-v1-1-f518960eaeda@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S
index 4328895dfc8763f6f63c540f27c8976eaf3da7d6..547d077e351727b4edc237ea5d4e136d8d743b4a 100644 (file)
--- 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