The PMU unit tests fail with an UNDEF exception when no PMU
is available (although KVM hasn't been totally consistent
with that in the past).

This is caused by PMCR_EL0 being read *before* ID_AA64DFR0_EL1
is checked for the PMU version.

Move the PMCR_EL0 access to a reasonable place, which allows the
test to soft-fail gracefully.

Fixes: 784ee933fa5f ("arm: pmu: Introduce defines for PMU versions")
Reported-by: Andrew Walbran <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
---
 arm/pmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arm/pmu.c b/arm/pmu.c
index cc959e6..15c542a 100644
--- a/arm/pmu.c
+++ b/arm/pmu.c
@@ -988,7 +988,7 @@ static void pmccntr64_test(void)
 /* Return FALSE if no PMU found, otherwise return TRUE */
 static bool pmu_probe(void)
 {
-       uint32_t pmcr = get_pmcr();
+       uint32_t pmcr;
        uint8_t implementer;
 
        pmu.version = get_pmu_version();
@@ -997,6 +997,7 @@ static bool pmu_probe(void)
 
        report_info("PMU version: 0x%x", pmu.version);
 
+       pmcr = get_pmcr();
        implementer = (pmcr >> PMU_PMCR_IMP_SHIFT) & PMU_PMCR_IMP_MASK;
        report_info("PMU implementer/ID code: %#"PRIx32"(\"%c\")/%#"PRIx32,
                    (pmcr >> PMU_PMCR_IMP_SHIFT) & PMU_PMCR_IMP_MASK,
-- 
2.30.0

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