feat(cpus): workaround for Cortex-A520(2938996) and Cortex-X4(2726228)
This patch implements errata functions for two errata, both of them
disable TRBE as a workaround. This patch doesn't have functions
that disable TRBE but only implemented helper functions that are
used to detect cores affected by Errata 2938996(Cortex-A520) & 2726228(Cortex-X4)
Cortex-X4 SDEN documentation:
https://developer.arm.com/documentation/SDEN2432808/latest
Cortex-A520 SDEN Documentation:
https://developer.arm.com/documentation/SDEN-2444153/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I8f886a1c21698f546a0996c719cc27dc0a23633a
diff --git a/lib/cpus/aarch64/cortex_a520.S b/lib/cpus/aarch64/cortex_a520.S
index 74ecbf7..b8f1468 100644
--- a/lib/cpus/aarch64/cortex_a520.S
+++ b/lib/cpus/aarch64/cortex_a520.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2021-2023, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2024, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -11,6 +11,9 @@
#include <cpu_macros.S>
#include <plat_macros.S>
+/* .global erratum_cortex_a520_2938996_wa */
+.global check_erratum_cortex_a520_2938996
+
/* Hardware handled coherency */
#if HW_ASSISTED_COHERENCY == 0
#error "Cortex A520 must be compiled with HW_ASSISTED_COHERENCY enabled"
@@ -32,6 +35,25 @@
workaround_reset_end cortex_a520, ERRATUM(2858100)
check_erratum_ls cortex_a520, ERRATUM(2858100), CPU_REV(0, 1)
+
+workaround_runtime_start cortex_a520, ERRATUM(2938996), ERRATA_A520_2938996, CORTEX_A520_MIDR
+workaround_runtime_end cortex_a520, ERRATUM(2938996)
+
+check_erratum_custom_start cortex_a520, ERRATUM(2938996)
+
+ /* This erratum needs to be enabled for r0p0 and r0p1.
+ * Check if revision is less than or equal to r0p1.
+ */
+
+#if ERRATA_A520_2938996
+ mov x1, #1
+ b cpu_rev_var_ls
+#else
+ mov x0, #ERRATA_MISSING
+#endif
+ ret
+check_erratum_custom_end cortex_a520, ERRATUM(2938996)
+
/* ----------------------------------------------------
* HW will do the cache maintenance while powering down
* ----------------------------------------------------
diff --git a/lib/cpus/aarch64/cortex_x4.S b/lib/cpus/aarch64/cortex_x4.S
index 9f822af..7c9a5a4 100644
--- a/lib/cpus/aarch64/cortex_x4.S
+++ b/lib/cpus/aarch64/cortex_x4.S
@@ -22,10 +22,30 @@
#error "Cortex X4 supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0"
#endif
+.global check_erratum_cortex_x4_2726228
+
#if WORKAROUND_CVE_2022_23960
wa_cve_2022_23960_bhb_vector_table CORTEX_X4_BHB_LOOP_COUNT, cortex_x4
#endif /* WORKAROUND_CVE_2022_23960 */
+workaround_runtime_start cortex_x4, ERRATUM(2726228), ERRATA_X4_2726228, CORTEX_X4_MIDR
+workaround_runtime_end cortex_x4, ERRATUM(2726228)
+
+check_erratum_custom_start cortex_x4, ERRATUM(2726228)
+
+ /* This erratum needs to be enabled for r0p0 and r0p1.
+ * Check if revision is less than or equal to r0p1.
+ */
+
+#if ERRATA_X4_2726228
+ mov x1, #1
+ b cpu_rev_var_ls
+#else
+ mov x0, #ERRATA_MISSING
+#endif
+ ret
+check_erratum_custom_end cortex_x4, ERRATUM(2726228)
+
workaround_runtime_start cortex_x4, ERRATUM(2740089), ERRATA_X4_2740089
/* dsb before isb of power down sequence */
dsb sy
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index c9ff110..1a9ee72 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -823,6 +823,10 @@
# cpu and is fixed in r0p1.
CPU_FLAG_LIST += ERRATA_X4_2701112
+# Flag to apply erratum 2726228 workaround during warmboot. This erratum
+# applies to all revisions <= r0p1 of the Cortex-X4 cpu, it is fixed in r0p2.
+CPU_FLAG_LIST += ERRATA_X4_2726228
+
# Flag to apply erratum 2740089 workaround during powerdown. This erratum
# applies to all revisions <= r0p1 of the Cortex-X4 cpu, it is fixed in r0p2.
CPU_FLAG_LIST += ERRATA_X4_2740089
@@ -896,6 +900,10 @@
# applies to revision r0p0 and r0p1 of the Cortex-A520 cpu and is still open.
CPU_FLAG_LIST += ERRATA_A520_2858100
+# Flag to apply erratum 2938996 workaround during reset. This erratum
+# applies to revision r0p0 and r0p1 of the Cortex-A520 cpu and is fixed in r0p2.
+CPU_FLAG_LIST += ERRATA_A520_2938996
+
# Flag to apply erratum 2331132 workaround during reset. This erratum applies
# to revisions r0p0, r0p1 and r0p2. It is still open.
CPU_FLAG_LIST += ERRATA_V2_2331132