errata: workaround for Cortex A77 errata 1791578
Cortex A77 erratum 1791578 is a Cat B erratum present in r0p0, r1p0,
and r1p1 of the A77 processor core, it is still open.
SDEN can be found here:
https://documentation-service.arm.com/static/60a63a3c982fc7708ac1c8b1
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Ib4b963144f880002de308def12744b982d3df868
diff --git a/lib/cpus/aarch64/cortex_a77.S b/lib/cpus/aarch64/cortex_a77.S
index 06b23d9..8c8f4d3 100644
--- a/lib/cpus/aarch64/cortex_a77.S
+++ b/lib/cpus/aarch64/cortex_a77.S
@@ -166,6 +166,34 @@
b cpu_rev_var_ls
endfunc check_errata_1946167
+ /* --------------------------------------------------
+ * Errata Workaround for Cortex A77 Errata #1791578.
+ * This applies to revisions r0p0, r1p0, and r1p1 and is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_a77_1791578_wa
+ /* Check workaround compatibility. */
+ mov x17, x30
+ bl check_errata_1791578
+ cbz x0, 1f
+
+ /* Set bit 2 in ACTLR2_EL1 */
+ mrs x1, CORTEX_A77_ACTLR2_EL1
+ orr x1, x1, #CORTEX_A77_ACTLR2_EL1_BIT_2
+ msr CORTEX_A77_ACTLR2_EL1, x1
+ isb
+1:
+ ret x17
+endfunc errata_a77_1791578_wa
+
+func check_errata_1791578
+ /* Applies to r0p0, r1p0, and r1p1 right now */
+ mov x1, #0x11
+ b cpu_rev_var_ls
+endfunc check_errata_1791578
+
/* -------------------------------------------------
* The CPU Ops reset function for Cortex-A77.
* Shall clobber: x0-x19
@@ -191,6 +219,11 @@
bl errata_a77_1946167_wa
#endif
+#if ERRATA_A77_1791578
+ mov x0, x18
+ bl errata_a77_1791578_wa
+#endif
+
ret x19
endfunc cortex_a77_reset_func
@@ -227,6 +260,7 @@
report_errata ERRATA_A77_1508412, cortex_a77, 1508412
report_errata ERRATA_A77_1925769, cortex_a77, 1925769
report_errata ERRATA_A77_1946167, cortex_a77, 1946167
+ report_errata ERRATA_A77_1791578, cortex_a77, 1791578
ldp x8, x30, [sp], #16
ret
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index fb33346..924c8d6 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -294,6 +294,10 @@
# only to revision <= r1p1 of the Cortex A77 cpu.
ERRATA_A77_1946167 ?=0
+# Flag to apply erratum 1791578 workaround during reset. This erratum applies
+# to revisions r0p0, r1p0, and r1p1, it is still open.
+ERRATA_A77_1791578 ?=0
+
# Flag to apply erratum 1688305 workaround during reset. This erratum applies
# to revisions r0p0 - r1p0 of the A78 cpu.
ERRATA_A78_1688305 ?=0
@@ -593,6 +597,10 @@
$(eval $(call assert_boolean,ERRATA_A77_1946167))
$(eval $(call add_define,ERRATA_A77_1946167))
+# Process ERRATA_A77_1791578 flag
+$(eval $(call assert_boolean,ERRATA_A77_1791578))
+$(eval $(call add_define,ERRATA_A77_1791578))
+
# Process ERRATA_A78_1688305 flag
$(eval $(call assert_boolean,ERRATA_A78_1688305))
$(eval $(call add_define,ERRATA_A78_1688305))