fix(pmu): add sensible default for MDCR_EL2

When TF-A is set to save and restore EL2 registers it initially zeroes
all of them so that it does not leak any information. However,
MDCR_EL2.HPMN of 0 is poorly defined when FEAT_HPMN0 is not implemented.
Set it to its hardware reset value so that lower ELs don't inherit a
wrong value.

Signed-off-by: Boyan Karatotev <>
Change-Id: I8055005ef9b6eaafefa13b62a0b41289079fdd23
1 file changed