Add workaround for errata 1073348 for Cortex-A76
Concurrent instruction TLB miss and mispredicted return instruction
might fetch wrong instruction stream. Set bit 6 of CPUACTLR_EL1 to
prevent this.
Change-Id: I2da4f30cd2df3f5e885dd3c4825c557492d1ac58
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 bbfc863..1f23b5b 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -147,6 +147,9 @@
For Cortex-A76, the following errata build flags are defined :
+- ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
+ CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
+
- ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
diff --git a/include/lib/cpus/aarch64/cortex_a76.h b/include/lib/cpus/aarch64/cortex_a76.h
index 52ab92e..c2af8ca 100644
--- a/include/lib/cpus/aarch64/cortex_a76.h
+++ b/include/lib/cpus/aarch64/cortex_a76.h
@@ -23,6 +23,10 @@
/*******************************************************************************
* CPU Auxiliary Control register specific definitions.
******************************************************************************/
+#define CORTEX_A76_CPUACTLR_EL1 S3_0_C15_C1_0
+
+#define CORTEX_A76_CPUACTLR_EL1_DISABLE_STATIC_PREDICTION (ULL(1) << 6)
+
#define CORTEX_A76_CPUACTLR2_EL1 S3_0_C15_C1_1
#define CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE (ULL(1) << 16)
diff --git a/lib/cpus/aarch64/cortex_a76.S b/lib/cpus/aarch64/cortex_a76.S
index 6bf8845..ac51343 100644
--- a/lib/cpus/aarch64/cortex_a76.S
+++ b/lib/cpus/aarch64/cortex_a76.S
@@ -190,6 +190,34 @@
end_vector_entry cortex_a76_serror_aarch32
/* --------------------------------------------------
+ * Errata Workaround for Cortex A76 Errata #1073348.
+ * This applies only to revision <= r1p0 of Cortex A76.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_a76_1073348_wa
+ /*
+ * Compare x0 against revision r1p0
+ */
+ mov x17, x30
+ bl check_errata_1073348
+ cbz x0, 1f
+ mrs x1, CORTEX_A76_CPUACTLR_EL1
+ orr x1, x1 ,#CORTEX_A76_CPUACTLR_EL1_DISABLE_STATIC_PREDICTION
+ msr CORTEX_A76_CPUACTLR_EL1, x1
+ isb
+1:
+ ret x17
+ endfunc errata_a76_1073348_wa
+
+func check_errata_1073348
+ mov x1, #0x10
+ b cpu_rev_var_ls
+endfunc check_errata_1073348
+
+ /* --------------------------------------------------
* Errata Workaround for Cortex A76 Errata #1130799.
* This applies only to revision <= r2p0 of Cortex A76.
* Inputs:
@@ -272,6 +300,11 @@
bl cpu_get_rev_var
mov x18, x0
+#if ERRATA_A76_1073348
+ mov x0, x18
+ bl errata_a76_1073348_wa
+#endif
+
#if ERRATA_A76_1130799
mov x0, x18
bl errata_a76_1130799_wa
@@ -344,6 +377,7 @@
* Report all errata. The revision-variant information is passed to
* checking functions of each errata.
*/
+ report_errata ERRATA_A76_1073348, cortex_a76, 1073348
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
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 3dcaecf..02208f0 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -131,6 +131,10 @@
# only to revision <= r0p0 of the Cortex A75 cpu.
ERRATA_A75_790748 ?=0
+# Flag to apply erratum 1073348 workaround during reset. This erratum applies
+# only to revision <= r1p0 of the Cortex A76 cpu.
+ERRATA_A76_1073348 ?=0
+
# Flag to apply erratum 1130799 workaround during reset. This erratum applies
# only to revision <= r2p0 of the Cortex A76 cpu.
ERRATA_A76_1130799 ?=0
@@ -220,6 +224,10 @@
$(eval $(call assert_boolean,ERRATA_A75_790748))
$(eval $(call add_define,ERRATA_A75_790748))
+# Process ERRATA_A76_1073348 flag
+$(eval $(call assert_boolean,ERRATA_A76_1073348))
+$(eval $(call add_define,ERRATA_A76_1073348))
+
# Process ERRATA_A76_1130799 flag
$(eval $(call assert_boolean,ERRATA_A76_1130799))
$(eval $(call add_define,ERRATA_A76_1130799))