fix(cpus): workaround for Cortex-X4 erratum 3076789
Cortex-X4 erratum 3076789 is a Cat B erratum that is present
in revisions r0p0, r0p1 and is fixed in r0p2.
The workaround is to set chicken bits CPUACTLR3_EL1[14:13]=0b11
and CPUACTLR_EL1[52] = 1.
Expected performance degradation is < 0.5%, but isolated
benchmark components might see higher impact.
SDEN documentation:
https://developer.arm.com/documentation/SDEN2432808/latest
Change-Id: Ib100bfab91efdb6330fdcdac127bcc5732d59196
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 5230cdc..fda43dc 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_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.
+
For Cortex-A510, the following errata build flags are defined :
- ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
diff --git a/include/lib/cpus/aarch64/cortex_x4.h b/include/lib/cpus/aarch64/cortex_x4.h
index b16170c..f701216 100644
--- a/include/lib/cpus/aarch64/cortex_x4.h
+++ b/include/lib/cpus/aarch64/cortex_x4.h
@@ -26,6 +26,7 @@
/*******************************************************************************
* CPU Auxiliary control register specific definitions
******************************************************************************/
+#define CORTEX_X4_CPUACTLR_EL1 S3_0_C15_C1_0
#define CORTEX_X4_CPUACTLR3_EL1 S3_0_C15_C1_2
#define CORTEX_X4_CPUACTLR4_EL1 S3_0_C15_C1_3
diff --git a/lib/cpus/aarch64/cortex_x4.S b/lib/cpus/aarch64/cortex_x4.S
index 75b2766..8820de5 100644
--- a/lib/cpus/aarch64/cortex_x4.S
+++ b/lib/cpus/aarch64/cortex_x4.S
@@ -75,6 +75,14 @@
check_erratum_ls cortex_x4, ERRATUM(2897503), 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)
+ sysreg_bit_set CORTEX_X4_CPUACTLR_EL1, BIT(52)
+workaround_reset_end cortex_x4, ERRATUM(3076789)
+
+check_erratum_ls cortex_x4, ERRATUM(3076789), CPU_REV(0, 1)
+
workaround_reset_start cortex_x4, CVE(2022, 23960), WORKAROUND_CVE_2022_23960
#if IMAGE_BL31
/*
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 2cbbdd2..4c20785 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 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
+
# Flag to apply erratum 1922240 workaround during reset. This erratum applies
# to revision r0p0 of the Cortex-A510 cpu and is fixed in r0p1.
CPU_FLAG_LIST += ERRATA_A510_1922240