AArch64: Enable MPAM for lower ELs
Memory Partitioning And Monitoring is an Armv8.4 feature that enables
various memory system components and resources to define partitions.
Software running at various ELs can then assign themselves to the
desired partition to control their performance aspects.
With this patch, when ENABLE_MPAM_FOR_LOWER_ELS is set to 1, EL3 allows
lower ELs to access their own MPAM registers without trapping to EL3.
This patch however doesn't make use of partitioning in EL3; platform
initialisation code should configure and use partitions in EL3 if
required.
Change-Id: I5a55b6771ccaa0c1cffc05543d2116b60cbbcdcd
Co-authored-by: James Morse <james.morse@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/docs/user-guide.rst b/docs/user-guide.rst
index 2b90bec..2ef7c61 100644
--- a/docs/user-guide.rst
+++ b/docs/user-guide.rst
@@ -350,6 +350,17 @@
that is only required for the assertion and does not fit in the assertion
itself.
+- ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM
+ feature. MPAM is an optional Armv8.4 extension that enables various memory
+ system components and resources to define partitions; software running at
+ various ELs can assign themselves to desired partition to control their
+ performance aspects.
+
+ When this option is set to ``1``, EL3 allows lower ELs to access their own
+ MPAM registers without trapping into EL3. This option doesn't make use of
+ partitioning in EL3, however. Platform initialisation code should configure
+ and use partitions in EL3 as required. This option defaults to ``0``.
+
- ``ENABLE_PMF``: Boolean option to enable support for optional Performance
Measurement Framework(PMF). Default is 0.