errata: workaround for Cortex-A710 erratum 2017096
Cortex-A710 erratum 2017096 is a Cat B erratum that applies to
revisions r0p0, r1p0 & r2p0 and is still open. The workaround is to
set CPUECLTR_EL1[8] to 1 which disables store issue prefetching.
SDEN can be found here:
https://developer.arm.com/documentation/SDEN1775101/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: If5f61ec30dbc2fab7f2c68663996057086e374e3
diff --git a/lib/cpus/aarch64/cortex_a710.S b/lib/cpus/aarch64/cortex_a710.S
index ac2517c..75b7647 100644
--- a/lib/cpus/aarch64/cortex_a710.S
+++ b/lib/cpus/aarch64/cortex_a710.S
@@ -133,6 +133,33 @@
b cpu_rev_var_ls
endfunc check_errata_2055002
+/* -------------------------------------------------------------
+ * Errata Workaround for Cortex-A710 Erratum 2017096.
+ * This applies to revisions r0p0, r1p0 and r2p0 of Cortex-A710.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * -------------------------------------------------------------
+ */
+func errata_a710_2017096_wa
+ /* Compare x0 against revision r0p0 to r2p0 */
+ mov x17, x30
+ bl check_errata_2017096
+ cbz x0, 1f
+ mrs x1, CORTEX_A710_CPUECTLR_EL1
+ orr x1, x1, CORTEX_A710_CPUECTLR_EL1_PFSTIDIS_BIT
+ msr CORTEX_A710_CPUECTLR_EL1, x1
+
+1:
+ ret x17
+endfunc errata_a710_2017096_wa
+
+func check_errata_2017096
+ /* Applies to r0p0, r1p0, r2p0 */
+ mov x1, #0x20
+ b cpu_rev_var_ls
+endfunc check_errata_2017096
+
/* ----------------------------------------------------
* HW will do the cache maintenance while powering down
* ----------------------------------------------------
@@ -166,6 +193,7 @@
report_errata ERRATA_A710_1987031, cortex_a710, 1987031
report_errata ERRATA_A710_2081180, cortex_a710, 2081180
report_errata ERRATA_A710_2055002, cortex_a710, 2055002
+ report_errata ERRATA_A710_2017096, cortex_a710, 2017096
ldp x8, x30, [sp], #16
ret
@@ -196,6 +224,10 @@
bl errata_a710_2055002_wa
#endif
+#if ERRATA_A710_2017096
+ mov x0, x18
+ bl errata_a710_2017096_wa
+#endif
isb
ret x19
endfunc cortex_a710_reset_func
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index fe66fbb..a630526 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -433,6 +433,10 @@
# to revision r1p0, r2p0 of the Cortex-A710 cpu and is still open.
ERRATA_A710_2055002 ?=0
+# Flag to apply erratum 2017096 workaround during reset. This erratum applies
+# to revision r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is still open.
+ERRATA_A710_2017096 ?=0
+
# Flag to apply DSU erratum 798953. This erratum applies to DSUs revision r0p0.
# Applying the workaround results in higher DSU power consumption on idle.
ERRATA_DSU_798953 ?=0
@@ -798,6 +802,10 @@
$(eval $(call assert_boolean,ERRATA_A710_2055002))
$(eval $(call add_define,ERRATA_A710_2055002))
+# Process ERRATA_A710_2017096 flag
+$(eval $(call assert_boolean,ERRATA_A710_2017096))
+$(eval $(call add_define,ERRATA_A710_2017096))
+
# Process ERRATA_DSU_798953 flag
$(eval $(call assert_boolean,ERRATA_DSU_798953))
$(eval $(call add_define,ERRATA_DSU_798953))