Cortex-A55: Implement workaround for erratum 778703
Change-Id: I094e5cb2c44618e7a4116af5fbb6b18078a79951
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
diff --git a/lib/cpus/aarch64/cortex_a55.S b/lib/cpus/aarch64/cortex_a55.S
index 018c9db..20d5fe4 100644
--- a/lib/cpus/aarch64/cortex_a55.S
+++ b/lib/cpus/aarch64/cortex_a55.S
@@ -39,6 +39,49 @@
b cpu_rev_var_ls
endfunc check_errata_768277
+ /* ------------------------------------------------------------------
+ * Errata Workaround for Cortex A55 Errata #778703.
+ * This applies only to revision r0p0 of Cortex A55 where L2 cache is
+ * not configured.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * ------------------------------------------------------------------
+ */
+func errata_a55_778703_wa
+ /*
+ * Compare x0 against revision r0p0 and check that no private L2 cache
+ * is configured
+ */
+ mov x17, x30
+ bl check_errata_778703
+ cbz x0, 1f
+ mrs x1, CORTEX_A55_CPUECTLR_EL1
+ orr x1, x1, #CORTEX_A55_CPUECTLR_EL1_L1WSCTL
+ msr CORTEX_A55_CPUECTLR_EL1, x1
+ mrs x1, CORTEX_A55_CPUACTLR_EL1
+ orr x1, x1, #CORTEX_A55_CPUACTLR_EL1_DISABLE_WRITE_STREAMING
+ msr CORTEX_A55_CPUACTLR_EL1, x1
+ isb
+1:
+ ret x17
+endfunc errata_a55_778703_wa
+
+func check_errata_778703
+ mov x16, x30
+ mov x1, #0x00
+ bl cpu_rev_var_ls
+ /*
+ * Check that no private L2 cache is configured
+ */
+ mrs x1, CORTEX_A55_CLIDR_EL1
+ and x1, x1, CORTEX_A55_CLIDR_EL1_CTYPE3
+ cmp x1, #0
+ mov x2, #ERRATA_NOT_APPLIES
+ csel x0, x0, x2, eq
+ ret x16
+endfunc check_errata_778703
+
func cortex_a55_reset_func
mov x19, x30
@@ -54,6 +97,11 @@
bl errata_a55_768277_wa
#endif
+#if ERRATA_A55_778703
+ mov x0, x18
+ bl errata_a55_778703_wa
+#endif
+
ret x19
endfunc cortex_a55_reset_func
@@ -88,6 +136,7 @@
*/
report_errata ERRATA_DSU_936184, cortex_a55, dsu_936184
report_errata ERRATA_A55_768277, cortex_a55, 768277
+ report_errata ERRATA_A55_778703, cortex_a55, 778703
ldp x8, x30, [sp], #16
ret
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 2ada0be..ee316b7 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -83,6 +83,10 @@
# only to revision r0p0 of the Cortex A55 cpu.
ERRATA_A55_768277 ?=0
+# Flag to apply erratum 778703 workaround during reset. This erratum applies
+# only to revision r0p0 of the Cortex A55 cpu.
+ERRATA_A55_778703 ?=0
+
# Flag to apply erratum 806969 workaround during reset. This erratum applies
# only to revision r0p0 of the Cortex A57 cpu.
ERRATA_A57_806969 ?=0
@@ -156,6 +160,10 @@
$(eval $(call assert_boolean,ERRATA_A55_768277))
$(eval $(call add_define,ERRATA_A55_768277))
+# Process ERRATA_A55_778703 flag
+$(eval $(call assert_boolean,ERRATA_A55_778703))
+$(eval $(call add_define,ERRATA_A55_778703))
+
# Process ERRATA_A57_806969 flag
$(eval $(call assert_boolean,ERRATA_A57_806969))
$(eval $(call add_define,ERRATA_A57_806969))