fix(cpus): workaround for Cortex-A78C erratum 1827430
Cortex-A78C erratum 1827430 is a Cat B erratum that applies to
revision r0p0 and is fixed in r0p1.
The workaround is to set the CPUECTLR_EL1[53] to 1, which disables
allocation of splintered pages in the L2 TLB.
SDEN documentation:
https://developer.arm.com/documentation/SDEN1707916/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: Ie68771bdd3bddeff54d06b6a456dad4a7fc27426
diff --git a/lib/cpus/aarch64/cortex_a78c.S b/lib/cpus/aarch64/cortex_a78c.S
index 71f0725..88bd291 100644
--- a/lib/cpus/aarch64/cortex_a78c.S
+++ b/lib/cpus/aarch64/cortex_a78c.S
@@ -18,6 +18,33 @@
#endif
/* --------------------------------------------------
+ * Errata Workaround for A78C Erratum 1827430.
+ * This applies to revision r0p0 of the Cortex A78C
+ * processor and is fixed in r0p1.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_a78c_1827430_wa
+ mov x17, x30
+ bl check_errata_1827430
+ cbz x0, 1f
+
+ /* Disable allocation of splintered pages in the L2 TLB */
+ mrs x1, CORTEX_A78C_CPUECTLR_EL1
+ orr x1, x1, CORTEX_A78C_CPUECTLR_EL1_MM_ASP_EN
+ msr CORTEX_A78C_CPUECTLR_EL1, x1
+1:
+ ret x17
+endfunc errata_a78c_1827430_wa
+
+func check_errata_1827430
+ /* Applies to revision r0p0 only */
+ mov x1, #0x00
+ b cpu_rev_var_ls
+endfunc check_errata_1827430
+
+/* --------------------------------------------------
* Errata Workaround for Cortex A78C Erratum 2376749.
* This applies to revision r0p1 and r0p2 of the A78C
* and is currently open. It is a Cat B erratum.
@@ -225,6 +252,11 @@
bl cpu_get_rev_var
mov x18, x0
+#if ERRATA_A78C_1827430
+ mov x0, x18
+ bl errata_a78c_1827430_wa
+#endif
+
#if ERRATA_A78C_2132064
mov x0, x18
bl errata_a78c_2132064_wa
@@ -299,6 +331,7 @@
* Report all errata. The revision-variant information is passed to
* checking functions of each errata.
*/
+ report_errata ERRATA_A78C_1827430, cortex_a78c, 1827430
report_errata ERRATA_A78C_2132064, cortex_a78c, 2132064
report_errata ERRATA_A78C_2242638, cortex_a78c, 2242638
report_errata ERRATA_A78C_2376749, cortex_a78c, 2376749
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index e26548f..13cf508 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -354,6 +354,10 @@
# to revisions r0p0 and r0p1 of the A78 AE cpu. It is still open.
CPU_FLAG_LIST += ERRATA_A78_AE_2395408
+# Flag to apply erratum 1827430 workaround during reset. This erratum applies
+# to revision r0p0 of the A78C cpu. It is fixed in r0p1.
+CPU_FLAG_LIST += ERRATA_A78C_1827430
+
# Flag to apply erratum 2132064 workaround during reset. This erratum applies
# to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
CPU_FLAG_LIST += ERRATA_A78C_2132064