uniphier: support read-only xlat tables

BL2 for this platform uses mmap_add_dynamic_region(), but BL31 and
BL32 (TSP) only use static mapping. So, BL31 and BL32 can make the
tables read-only after enabling MMU.

Enable ALLOW_RO_XLAT_TABLES by default.

Change-Id: Ib59c44697163629119888bb6abd47fa144f09ba3
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

plat/socionext/uniphier/platform.mk

@@ -14,6 +14,13 @@ override ENABLE_SVE_FOR_NS		:= 0
 # UNIPHIER_MEM_BASE so that all TF images are loaded at their link addresses.
 override ENABLE_PIE			:= 1
 
+ALLOW_RO_XLAT_TABLES			:= 1
+
+ifeq ($(ALLOW_RO_XLAT_TABLES),1)
+BL31_CFLAGS += -DPLAT_RO_XLAT_TABLES=1
+BL32_CFLAGS += -DPLAT_RO_XLAT_TABLES=1
+endif
+
 # Cortex-A53 revision r0p4-51rel0
 # needed for LD20, unneeded for LD11, PXs3 (no ACE)
 ERRATA_A53_855873		:= 1

plat/socionext/uniphier/uniphier_xlat_setup.c

@@ -10,6 +10,7 @@
 
 #include <common/debug.h>
 #include <lib/xlat_tables/xlat_tables_v2.h>
+#include <plat/common/platform.h>
 
 #include "uniphier.h"
 
@@ -65,4 +66,16 @@ void uniphier_mmap_setup(unsigned int soc)
 	init_xlat_tables();
 
 	enable_mmu(0);
+
+#if PLAT_RO_XLAT_TABLES
+	{
+		int ret;
+
+		ret = xlat_make_tables_readonly();
+		if (ret) {
+			ERROR("Failed to make translation tables read-only.");
+			plat_error_handler(ret);
+		}
+	}
+#endif
 }