fix(cpus): workaround for Cortex-A78C erratum 2779484
Cortex-A78C erratum 2779484 is a Cat B erratum that applies to
revisions r0p1 and r0p2 and is still open.
The workaround is to set the 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/SDEN2004089/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I9a8c16a845c3ba6eb2f17a5119aa6ca09a0d27ed
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 53b54b8..0f62778 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -369,6 +369,10 @@
Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
This erratum is still open.
+- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
+ Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
+ This erratum is still open.
+
For Cortex-X1 CPU, the following errata build flags are defined:
- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
diff --git a/include/lib/cpus/aarch64/cortex_a78c.h b/include/lib/cpus/aarch64/cortex_a78c.h
index 35e543c..18cba2c 100644
--- a/include/lib/cpus/aarch64/cortex_a78c.h
+++ b/include/lib/cpus/aarch64/cortex_a78c.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2021-2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2023, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -34,6 +34,11 @@
#define CORTEX_A78C_CPUPWRCTLR_EL1_CORE_PWRDN_EN_BIT U(1)
/*******************************************************************************
+ * CPU Auxiliary Control register 3 specific definitions.
+ ******************************************************************************/
+#define CORTEX_A78C_ACTLR3_EL1 S3_0_C15_C1_2
+
+/*******************************************************************************
* CPU Implementation Specific Selected Instruction registers
******************************************************************************/
#define CORTEX_A78C_IMP_CPUPSELR_EL3 S3_6_C15_C8_0
diff --git a/lib/cpus/aarch64/cortex_a78c.S b/lib/cpus/aarch64/cortex_a78c.S
index 5cdce89..71f0725 100644
--- a/lib/cpus/aarch64/cortex_a78c.S
+++ b/lib/cpus/aarch64/cortex_a78c.S
@@ -177,6 +177,36 @@
b cpu_rev_var_ls
endfunc check_errata_2772121
+/* --------------------------------------------------
+ * Errata Workaround for Cortex A78C Errata 2779484.
+ * This applies to revisions r0p1 and r0p2.
+ * It is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x1, x17
+ * --------------------------------------------------
+ */
+func errata_a78c_2779484_wa
+ /* Check revision. */
+ mov x17, x30
+ bl check_errata_2779484
+ cbz x0, 1f
+
+ /* Apply the workaround */
+ mrs x1, CORTEX_A78C_ACTLR3_EL1
+ orr x1, x1, #BIT(47)
+ msr CORTEX_A78C_ACTLR3_EL1, x1
+
+1:
+ ret x17
+endfunc errata_a78c_2779484_wa
+
+func check_errata_2779484
+ /* Applies to r0p1 and r0p2*/
+ mov x1, #0x01
+ mov x2, #0x02
+ b cpu_rev_var_range
+endfunc check_errata_2779484
+
func check_errata_cve_2022_23960
#if WORKAROUND_CVE_2022_23960
mov x0, #ERRATA_APPLIES
@@ -215,6 +245,11 @@
bl errata_a78c_2395411_wa
#endif
+#if ERRATA_A78C_2779484
+ mov x0, x18
+ bl errata_a78c_2779484_wa
+#endif
+
#if IMAGE_BL31 && WORKAROUND_CVE_2022_23960
/*
* The Cortex-A78c generic vectors are overridden to apply errata
@@ -269,6 +304,7 @@
report_errata ERRATA_A78C_2376749, cortex_a78c, 2376749
report_errata ERRATA_A78C_2395411, cortex_a78c, 2395411
report_errata ERRATA_A78C_2772121, cortex_a78c, 2772121
+ report_errata ERRATA_A78C_2779484, cortex_a78c, 2779484
report_errata WORKAROUND_CVE_2022_23960, cortex_a78c, cve_2022_23960
ldp x8, x30, [sp], #16
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 112d8cb..0f10061 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -407,6 +407,10 @@
# applies to revisions r0p0, r0p1 and r0p2 of the A78C cpu. It is still open.
ERRATA_A78C_2772121 ?=0
+# Flag to apply erratum 2779484 workaround during reset. This erratum
+# applies to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
+ERRATA_A78C_2779484 ?=0
+
# Flag to apply erratum 1821534 workaround during reset. This erratum applies
# to revisions r0p0 - r1p0 of the X1 cpu and fixed in r1p1.
ERRATA_X1_1821534 ?=0
@@ -1097,6 +1101,10 @@
$(eval $(call assert_boolean,ERRATA_A78C_2772121))
$(eval $(call add_define,ERRATA_A78C_2772121))
+# Process ERRATA_A78C_2779484 flag
+$(eval $(call assert_boolean,ERRATA_A78C_2779484))
+$(eval $(call add_define,ERRATA_A78C_2779484))
+
# Process ERRATA_X1_1821534 flag
$(eval $(call assert_boolean,ERRATA_X1_1821534))
$(eval $(call add_define,ERRATA_X1_1821534))