fix(cpus): workaround for Neoverse V1 errata 2779461
Neoverse V1 erratum 2779461 is a Cat B erratum that applies to
all revisions <=r1p2 and is still open.
The workaround sets CPUACTLR3_EL1[47] bit to 1. Setting this
bit might have a small impact on power and negligible impact
on performance.
SDEN documentation:https://developer.arm.com/documentation/SDEN1401781/latest
Change-Id: I367cda1779684638063d7292fda20ca6734e6f10
Signed-off-by: Sona Mathew <SonaRebecca.Mathew@arm.com>
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 4ae4e54..c4a0e15 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -472,6 +472,10 @@
CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
CPU. It is still open.
+- ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
+ CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
+ CPU. It is still open.
+
For Cortex-A710, the following errata build flags are defined :
- ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
diff --git a/include/lib/cpus/aarch64/neoverse_v1.h b/include/lib/cpus/aarch64/neoverse_v1.h
index 9c7e967..4c10484 100644
--- a/include/lib/cpus/aarch64/neoverse_v1.h
+++ b/include/lib/cpus/aarch64/neoverse_v1.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2019-2022, ARM Limited. All rights reserved.
+ * Copyright (c) 2019-2023, ARM Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -41,4 +41,6 @@
#define NEOVERSE_V1_ACTLR2_EL1_BIT_28 (ULL(1) << 28)
#define NEOVERSE_V1_ACTLR2_EL1_BIT_40 (ULL(1) << 40)
+#define NEOVERSE_V1_ACTLR3_EL1 S3_0_C15_C1_2
+
#endif /* NEOVERSE_V1_H */
diff --git a/lib/cpus/aarch64/neoverse_v1.S b/lib/cpus/aarch64/neoverse_v1.S
index c3a70ca..f9a5789 100644
--- a/lib/cpus/aarch64/neoverse_v1.S
+++ b/lib/cpus/aarch64/neoverse_v1.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2019-2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2023, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -486,6 +486,35 @@
b cpu_rev_var_ls
endfunc check_errata_2743093
+ /* ----------------------------------------------------
+ * Errata Workaround for Neoverse V1 Errata #2779461.
+ * This applies to revisions r0p0, r1p0, r1p1, and r1p2.
+ * It is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x1, x17
+ * ----------------------------------------------------
+ */
+func errata_neoverse_v1_2779461_wa
+ /* Check revision. */
+ mov x17, x30
+ bl check_errata_2779461
+ cbz x0, 1f
+
+ /* Apply the workaround */
+ mrs x1, NEOVERSE_V1_ACTLR3_EL1
+ orr x1, x1, #BIT(47)
+ msr NEOVERSE_V1_ACTLR3_EL1, x1
+
+1:
+ ret x17
+endfunc errata_neoverse_v1_2779461_wa
+
+func check_errata_2779461
+ /* Applies to r0p0, r1p0, r1p1, r1p2 */
+ mov x1, #CPU_REV(1, 2)
+ b cpu_rev_var_ls
+endfunc check_errata_2779461
+
func check_errata_cve_2022_23960
#if WORKAROUND_CVE_2022_23960
mov x0, #ERRATA_APPLIES
@@ -544,6 +573,7 @@
report_errata ERRATA_V1_2294912, neoverse_v1, 2294912
report_errata ERRATA_V1_2372203, neoverse_v1, 2372203
report_errata ERRATA_V1_2743093, neoverse_v1, 2743093
+ report_errata ERRATA_V1_2779461, neoverse_v1, 2779461
report_errata WORKAROUND_CVE_2022_23960, neoverse_v1, cve_2022_23960
ldp x8, x30, [sp], #16
@@ -622,6 +652,11 @@
bl errata_neoverse_v1_2372203_wa
#endif
+#if ERRATA_V1_2779461
+ mov x0, x18
+ bl errata_neoverse_v1_2779461_wa
+#endif
+
#if IMAGE_BL31 && WORKAROUND_CVE_2022_23960
/*
* The Neoverse-V1 generic vectors are overridden to apply errata
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index ae6baa7..4d50c1b 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -526,6 +526,11 @@
# still open.
ERRATA_V1_2743093 ?=0
+# Flag to apply erratum 2779461 workaround during powerdown. This erratum
+# applies to revisions r0p0, r1p0, r1p1 and r1p2 of the Neoverse V1 cpu and is
+# still open.
+ERRATA_V1_2779461 ?=0
+
# Flag to apply erratum 1987031 workaround during reset. This erratum applies
# to revisions r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is still open.
ERRATA_A710_1987031 ?=0
@@ -1194,6 +1199,10 @@
$(eval $(call assert_boolean,ERRATA_V1_2743093))
$(eval $(call add_define,ERRATA_V1_2743093))
+# Process ERRATA_V1_2779461 flag
+$(eval $(call assert_boolean,ERRATA_V1_2779461))
+$(eval $(call add_define,ERRATA_V1_2779461))
+
# Process ERRATA_A710_1987031 flag
$(eval $(call assert_boolean,ERRATA_A710_1987031))
$(eval $(call add_define,ERRATA_A710_1987031))