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authorJoel Hutton <Joel.Hutton@arm.com>2019-04-10 12:52:52 +0100
committerJoel Hutton <Joel.Hutton@arm.com>2019-04-12 10:10:32 +0000
commitdd4cf2c74566c18adbb04944e6bf7a974276ec16 (patch)
tree2a2f89a32d67a4e97164aef6c2394360e6bc633a /lib/cpus
parentc554e1ad82b0cf874a76e4685a4da61da14da1fe (diff)
downloadtrusted-firmware-a-dd4cf2c74566c18adbb04944e6bf7a974276ec16.tar.gz
Cortex A9:errata 794073 workaround
On Cortex A9 an errata can cause the processor to violate the rules for speculative fetches when the MMU is off but branch prediction has not been disabled. The workaround for this is to execute an Invalidate Entire Branch Prediction Array (BPIALL) followed by a DSB. see:http://arminfo.emea.arm.com/help/topic/com.arm.doc.uan0009d/UAN0009_cortex_a9_errata_r4.pdf for more details. Change-Id: I9146c1fa7563a79f4e15b6251617b9620a587c93 Signed-off-by: Joel Hutton <Joel.Hutton@arm.com>
Diffstat (limited to 'lib/cpus')
-rw-r--r--lib/cpus/aarch32/cortex_a9.S10
-rw-r--r--lib/cpus/cpu-ops.mk7
2 files changed, 17 insertions, 0 deletions
diff --git a/lib/cpus/aarch32/cortex_a9.S b/lib/cpus/aarch32/cortex_a9.S
index 1fb10b2054..720034310a 100644
--- a/lib/cpus/aarch32/cortex_a9.S
+++ b/lib/cpus/aarch32/cortex_a9.S
@@ -35,6 +35,15 @@ func cortex_a9_enable_smp
bx lr
endfunc cortex_a9_enable_smp
+func check_errata_a9_794073
+#if ERRATA_A9_794073
+ mov r0, #ERRATA_APPLIES
+#else
+ mov r0, #ERRATA_MISSING
+#endif
+ bx lr
+endfunc check_errata_cve_2017_5715
+
func check_errata_cve_2017_5715
#if WORKAROUND_CVE_2017_5715
mov r0, #ERRATA_APPLIES
@@ -59,6 +68,7 @@ func cortex_a9_errata_report
* checking functions of each errata.
*/
report_errata WORKAROUND_CVE_2017_5715, cortex_a9, cve_2017_5715
+ report_errata ERRATA_A9_794073, cortex_a9, a9_79407
pop {r12, lr}
bx lr
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index c42eb1cde5..c7e8b33a3c 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -53,6 +53,9 @@ endif
# These should be enabled by the platform if the erratum workaround needs to be
# applied.
+# Flag to apply erratum 794073 workaround when disabling mmu.
+ERRATA_A9_794073 ?=0
+
# Flag to apply erratum 816470 workaround during power down. This erratum
# applies only to revision >= r3p0 of the Cortex A15 cpu.
ERRATA_A15_816470 ?=0
@@ -212,6 +215,10 @@ ERRATA_N1_1043202 ?=1
# higher DSU power consumption on idle.
ERRATA_DSU_936184 ?=0
+# Process ERRATA_A9_794073 flag
+$(eval $(call assert_boolean,ERRATA_A9_794073))
+$(eval $(call add_define,ERRATA_A9_794073))
+
# Process ERRATA_A15_816470 flag
$(eval $(call assert_boolean,ERRATA_A15_816470))
$(eval $(call add_define,ERRATA_A15_816470))