Add workaround for errata 1220197 for Cortex-A76
Streaming store under specific conditions might cause deadlock or data
corruption. Set bit 25:24 of CPUECTLR_EL1, which disables write
streaming to the L2 to prevent this.
Change-Id: Ib5cabb997b35ada78b27e75787afd610ea606dcf
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst
index 6a33441..bbfc863 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -150,6 +150,9 @@
- ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
+- ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
+ CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
+
DSU Errata Workarounds
----------------------
diff --git a/include/lib/cpus/aarch64/cortex_a76.h b/include/lib/cpus/aarch64/cortex_a76.h
index 5779d7b..52ab92e 100644
--- a/include/lib/cpus/aarch64/cortex_a76.h
+++ b/include/lib/cpus/aarch64/cortex_a76.h
@@ -18,6 +18,8 @@
#define CORTEX_A76_CPUPWRCTLR_EL1 S3_0_C15_C2_7
#define CORTEX_A76_CPUECTLR_EL1 S3_0_C15_C1_4
+#define CORTEX_A76_CPUECTLR_EL1_WS_THR_L2 (ULL(3) << 24)
+
/*******************************************************************************
* CPU Auxiliary Control register specific definitions.
******************************************************************************/
diff --git a/lib/cpus/aarch64/cortex_a76.S b/lib/cpus/aarch64/cortex_a76.S
index 8438fa6..6bf8845 100644
--- a/lib/cpus/aarch64/cortex_a76.S
+++ b/lib/cpus/aarch64/cortex_a76.S
@@ -217,6 +217,34 @@
b cpu_rev_var_ls
endfunc check_errata_1130799
+ /* --------------------------------------------------
+ * Errata Workaround for Cortex A76 Errata #1220197.
+ * This applies only to revision <= r2p0 of Cortex A76.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_a76_1220197_wa
+/*
+ * Compare x0 against revision r2p0
+ */
+ mov x17, x30
+ bl check_errata_1220197
+ cbz x0, 1f
+ mrs x1, CORTEX_A76_CPUECTLR_EL1
+ orr x1, x1, #CORTEX_A76_CPUECTLR_EL1_WS_THR_L2
+ msr CORTEX_A76_CPUECTLR_EL1, x1
+ isb
+1:
+ ret x17
+endfunc errata_a76_1220197_wa
+
+func check_errata_1220197
+ mov x1, #0x20
+ b cpu_rev_var_ls
+endfunc check_errata_1220197
+
func check_errata_cve_2018_3639
#if WORKAROUND_CVE_2018_3639
mov x0, #ERRATA_APPLIES
@@ -242,11 +270,18 @@
func cortex_a76_reset_func
mov x19, x30
bl cpu_get_rev_var
+ mov x18, x0
#if ERRATA_A76_1130799
+ mov x0, x18
bl errata_a76_1130799_wa
#endif
+#if ERRATA_A76_1220197
+ mov x0, x18
+ bl errata_a76_1220197_wa
+#endif
+
#if WORKAROUND_CVE_2018_3639
/* If the PE implements SSBS, we don't need the dynamic workaround */
mrs x0, id_aa64pfr1_el1
@@ -310,6 +345,7 @@
* checking functions of each errata.
*/
report_errata ERRATA_A76_1130799, cortex_a76, 1130799
+ report_errata ERRATA_A76_1220197, cortex_a76, 1220197
report_errata WORKAROUND_CVE_2018_3639, cortex_a76, cve_2018_3639
report_errata ERRATA_DSU_936184, cortex_a76, dsu_936184
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 4fe8ea1..3dcaecf 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -135,6 +135,10 @@
# only to revision <= r2p0 of the Cortex A76 cpu.
ERRATA_A76_1130799 ?=0
+# Flag to apply erratum 1220197 workaround during reset. This erratum applies
+# only to revision <= r2p0 of the Cortex A76 cpu.
+ERRATA_A76_1220197 ?=0
+
# Flag to apply T32 CLREX workaround during reset. This erratum applies
# only to r0p0 and r1p0 of the Neoverse N1 cpu.
ERRATA_N1_1043202 ?=1
@@ -220,6 +224,10 @@
$(eval $(call assert_boolean,ERRATA_A76_1130799))
$(eval $(call add_define,ERRATA_A76_1130799))
+# Process ERRATA_A76_1220197 flag
+$(eval $(call assert_boolean,ERRATA_A76_1220197))
+$(eval $(call add_define,ERRATA_A76_1220197))
+
# Process ERRATA_N1_1043202 flag
$(eval $(call assert_boolean,ERRATA_N1_1043202))
$(eval $(call add_define,ERRATA_N1_1043202))