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/include/lib/cpus/aarch64/cortex_a78_ae.h b/include/lib/cpus/aarch64/cortex_a78_ae.h
index 90b6d6f..4108af5 100644
--- a/include/lib/cpus/aarch64/cortex_a78_ae.h
+++ b/include/lib/cpus/aarch64/cortex_a78_ae.h
@@ -1,6 +1,6 @@
/*
* Copyright (c) 2019-2022, ARM Limited. All rights reserved.
- * Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+ * Copyright (c) 2021-2022, NVIDIA Corporation. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -21,4 +21,10 @@
#define CORTEX_A78_AE_CPUECTLR_EL1 CORTEX_A78_CPUECTLR_EL1
#define CORTEX_A78_AE_CPUECTLR_EL1_BIT_8 CORTEX_A78_CPUECTLR_EL1_BIT_8
+/*******************************************************************************
+ * CPU Auxiliary Control register 2 specific definitions.
+ ******************************************************************************/
+#define CORTEX_A78_AE_ACTLR2_EL1 CORTEX_A78_ACTLR2_EL1
+#define CORTEX_A78_AE_ACTLR2_EL1_BIT_0 CORTEX_A78_ACTLR2_EL1_BIT_0
+
#endif /* CORTEX_A78_AE_H */