feat(cpufeat): add feature detection for FEAT_CSV2_3
This feature provides support to context save the
SCXTNUM_ELx register. FEAT_CSV2_3 implies the implementation
of FEAT_CSV2_2. FEAT_CSV2_3 is supported in AArch64 state only
and is an optional feature in Arm v8.0 implementations.
This patch adds feature detection for v8.9 feature FEAT_CSV2_3,
adds macros for ID_AA64PFR0_EL1.CSV2 bits [59:56] for detecting
FEAT_CSV2_3 and macro for ENABLE_FEAT_CSV2_3.
Change-Id: Ida9f31e832b5f11bd89eebd6cc9f10ddad755c14
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 077f598..cc20261 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -306,6 +306,13 @@
0 to 2, to align with the ``ENABLE_FEAT`` mechanism.
Default value is ``0``.
+- ``ENABLE_FEAT_CSV2_3``: Numeric value to enable support for ``FEAT_CSV2_3``
+ extension. This feature is supported in AArch64 state only and is an optional
+ feature available in Arm v8.0 implementations.
+ ``FEAT_CSV2_3`` implies the implementation of ``FEAT_CSV2_2``.
+ The flag can take values 0 to 2, to align with the ``ENABLE_FEAT``
+ mechanism. Default value is ``0``.
+
- ``ENABLE_FEAT_DIT``: Numeric value to enable ``FEAT_DIT`` (Data Independent
Timing) extension. It allows setting the ``DIT`` bit of PSTATE in EL3.
``FEAT_DIT`` is a mandatory architectural feature and is enabled from v8.4