fix(errata): workaround for Cortex A78 AE erratum 2376748
Cortex A78 AE erratum 2376748 is a Cat B erratum that applies
to revisions <= r0p1. It is still open.
The erratum states, "A PE executing a PLDW or PRFM PST instruction
that lies on a mispredicted branch path might cause a second PE
executing a store exclusive to the same cache line address to fail
continuously."
The erratum is avoided by setting CPUACTLR2_EL1[0] to 1 to force
PLDW/PFRM ST to behave like PLD/PRFM LD and not cause invalidations
to other PE caches. There might be a small performance degradation
to this workaround for certain workloads that share data.
SDEN is available at https://developer.arm.com/documentation/SDEN-1707912
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I93bd392a870d4584f3e12c8e4626dbe5a3a40a4d
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index b7d1168..13b447a 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -298,13 +298,17 @@
For Cortex-A78 AE, the following errata build flags are defined :
-- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to Cortex-A78
- AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This erratum is
- still open.
+- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
+ Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
+ This erratum is still open.
-- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to Cortex-A78
- AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This erratum is
- still open.
+- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
+ Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
+ erratum is still open.
+
+- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
+ Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
+ erratum is still open.
For Neoverse N1, the following errata build flags are defined :