fix(cpus): workaround for Cortex-X2 erratum 1901946
Cortex-X2 erratum 1901946 is a Cat B erratum that applies to
revision r1p0 and is fixed in r2p0.
The workaround is to set CPUACTLR4_EL1[15]. This has a small
performance impact.
SDEN documentation:
https://developer.arm.com/documentation/SDEN-1775100/latest
Change-Id: I5a65db60f06982191994db49815419c4d72506cf
Signed-off-by: John Powell <john.powell@arm.com>
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 0d6a5dd..9978202 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -741,6 +741,9 @@
For Cortex-X2, the following errata build flags are defined :
+- ``ERRATA_X2_1901946``: This applies errata 1901946 workaround to Cortex-X2
+ CPU. This needs to be enabled only for r1p0, it is fixed in r2p0.
+
- ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
it is still open.