fix(cpus): workaround for Cortex-X4 erratum 2923985
Cortex-X4 erratum 2923935 is a Cat B erratum that applies
to all revisions <= r0p1 and is fixed in r0p2.
The workaround is to set CPUACTLR4_EL1[11:10] to 0b11.
SDEN documentation:
https://developer.arm.com/documentation/SDEN-2432808/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I9207802ad479919a7f77c1271019fa2479e076ee
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index fda43dc..f1cb73b 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -843,6 +843,9 @@
- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
+- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
+ CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
+
- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
diff --git a/lib/cpus/aarch64/cortex_x4.S b/lib/cpus/aarch64/cortex_x4.S
index 320fd90..4ff0ea5 100644
--- a/lib/cpus/aarch64/cortex_x4.S
+++ b/lib/cpus/aarch64/cortex_x4.S
@@ -75,6 +75,12 @@
check_erratum_ls cortex_x4, ERRATUM(2897503), CPU_REV(0, 1)
+workaround_reset_start cortex_x4, ERRATUM(2923985), ERRATA_X4_2923985
+ sysreg_bit_set CORTEX_X4_CPUACTLR4_EL1, (BIT(11) | BIT(10))
+workaround_reset_end cortex_x4, ERRATUM(2923985)
+
+check_erratum_ls cortex_x4, ERRATUM(2923985), CPU_REV(0, 1)
+
workaround_reset_start cortex_x4, ERRATUM(3076789), ERRATA_X4_3076789
sysreg_bit_set CORTEX_X4_CPUACTLR3_EL1, BIT(14)
sysreg_bit_set CORTEX_X4_CPUACTLR3_EL1, BIT(13)
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 4c20785..4a04a9d 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -843,6 +843,10 @@
# to revisions r0p0 and r0p1 of the Cortex-X4 cpu. It is fixed in r0p2.
CPU_FLAG_LIST += ERRATA_X4_2897503
+# Flag to apply erratum 2923985 workaround on reset. This erratum applies
+# to revisions r0p0 and r0p1 of the Cortex-X4 cpu. It is fixed in r0p2.
+CPU_FLAG_LIST += ERRATA_X4_2923985
+
# Flag to apply erratum 3076789 workaround on reset. This erratum applies
# to revisions r0p0 and r0p1 of the Cortex-X4 cpu. It is fixed in r0p2.
CPU_FLAG_LIST += ERRATA_X4_3076789