Add support for Cortex-A57 erratum 826977 workaround
Change-Id: Icaacd19c4cef9c10d02adcc2f84a4d7c97d4bcfa
diff --git a/docs/cpu-specific-build-macros.md b/docs/cpu-specific-build-macros.md
index 94d05d5..c41cbff 100644
--- a/docs/cpu-specific-build-macros.md
+++ b/docs/cpu-specific-build-macros.md
@@ -63,6 +63,9 @@
* `ERRATA_A57_826974`: This applies errata 826974 workaround to Cortex-A57
CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
+* `ERRATA_A57_826977`: This applies errata 826977 workaround to Cortex-A57
+ CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
+
* `ERRATA_A57_828024`: This applies errata 828024 workaround to Cortex-A57
CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
diff --git a/include/lib/cpus/aarch64/cortex_a57.h b/include/lib/cpus/aarch64/cortex_a57.h
index 95c1f56..685b87b 100644
--- a/include/lib/cpus/aarch64/cortex_a57.h
+++ b/include/lib/cpus/aarch64/cortex_a57.h
@@ -62,6 +62,7 @@
#define CPUACTLR_EL1 S3_1_C15_C2_0 /* Instruction def. */
#define CPUACTLR_DIS_LOAD_PASS_DMB (1 << 59)
+#define CPUACTLR_GRE_NGRE_AS_NGNRE (1 << 54)
#define CPUACTLR_DIS_OVERREAD (1 << 52)
#define CPUACTLR_NO_ALLOC_WBWA (1 << 49)
#define CPUACTLR_DCC_AS_DCCI (1 << 44)
diff --git a/lib/cpus/aarch64/cortex_a57.S b/lib/cpus/aarch64/cortex_a57.S
index 25def1c..63cb757 100644
--- a/lib/cpus/aarch64/cortex_a57.S
+++ b/lib/cpus/aarch64/cortex_a57.S
@@ -194,6 +194,32 @@
endfunc errata_a57_826974_wa
/* ---------------------------------------------------
+ * Errata Workaround for Cortex A57 Errata #826977.
+ * This applies only to revision <= r1p1 of Cortex A57.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Clobbers : x0 - x5
+ * ---------------------------------------------------
+ */
+func errata_a57_826977_wa
+ /*
+ * Compare x0 against revision r1p1
+ */
+ cmp x0, #0x11
+ b.ls apply_826977
+#if LOG_LEVEL >= LOG_LEVEL_VERBOSE
+ b print_revision_warning
+#else
+ ret
+#endif
+apply_826977:
+ mrs x1, CPUACTLR_EL1
+ orr x1, x1, #CPUACTLR_GRE_NGRE_AS_NGNRE
+ msr CPUACTLR_EL1, x1
+ ret
+endfunc errata_a57_826977_wa
+
+ /* ---------------------------------------------------
* Errata Workaround for Cortex A57 Errata #828024.
* This applies only to revision <= r1p1 of Cortex A57.
* Inputs:
@@ -289,6 +315,11 @@
bl errata_a57_826974_wa
#endif
+#if ERRATA_A57_826977
+ mov x0, x15
+ bl errata_a57_826977_wa
+#endif
+
#if ERRATA_A57_828024
mov x0, x15
bl errata_a57_828024_wa
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 62de70f..aa808b6 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -78,6 +78,10 @@
# only to revision <= r1p1 of the Cortex A57 cpu.
ERRATA_A57_826974 ?=0
+# Flag to apply erratum 826977 workaround during reset. This erratum applies
+# only to revision <= r1p1 of the Cortex A57 cpu.
+ERRATA_A57_826977 ?=0
+
# Flag to apply erratum 828024 workaround during reset. This erratum applies
# only to revision <= r1p1 of the Cortex A57 cpu.
ERRATA_A57_828024 ?=0
@@ -106,6 +110,10 @@
$(eval $(call assert_boolean,ERRATA_A57_826974))
$(eval $(call add_define,ERRATA_A57_826974))
+# Process ERRATA_A57_826977 flag
+$(eval $(call assert_boolean,ERRATA_A57_826977))
+$(eval $(call add_define,ERRATA_A57_826977))
+
# Process ERRATA_A57_828024 flag
$(eval $(call assert_boolean,ERRATA_A57_828024))
$(eval $(call add_define,ERRATA_A57_828024))
