ARMv7 may not support large page addressing

ARCH_SUPPORTS_LARGE_PAGE_ADDRESSING allows build environment to
handle specific case when target ARMv7 core only supports 32bit MMU
descriptor mode.

If ARMv7 based platform does not set ARM_CORTEX_Ax=yes, platform
shall define ARMV7_SUPPORTS_LARGE_PAGE_ADDRESSING to enable
large page addressing support.
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

lib/xlat_tables/aarch32/xlat_tables.c

@@ -13,6 +13,10 @@
 #include <xlat_tables.h>
 #include "../xlat_tables_private.h"
 
+#if ARM_ARCH_MAJOR == 7 && !defined(ARMV7_SUPPORTS_LARGE_PAGE_ADDRESSING)
+#error ARMv7 target does not support LPAE MMU descriptors
+#endif
+
 #define XLAT_TABLE_LEVEL_BASE	\
        GET_XLAT_TABLE_LEVEL_BASE(PLAT_VIRT_ADDR_SPACE_SIZE)
 

lib/xlat_tables_v2/aarch32/xlat_tables_arch.c

@@ -14,6 +14,10 @@
 #include <xlat_tables_v2.h>
 #include "../xlat_tables_private.h"
 
+#if ARM_ARCH_MAJOR == 7 && !defined(ARMV7_SUPPORTS_LARGE_PAGE_ADDRESSING)
+#error ARMv7 target does not support LPAE MMU descriptors
+#endif
+
 #if ENABLE_ASSERTIONS
 unsigned long long xlat_arch_get_max_supported_pa(void)
 {

make_helpers/armv7-a-cpus.mk

@@ -31,3 +31,12 @@ march32-neon-$(ARM_WITH_NEON)	:= -mfpu=neon
 march32-set-yes			?= -march=armv7-a
 march32-directive		:= ${march32-set-yes} ${march32-neon-yes}
 endif
+
+# Platform may override these extension support directives:
+#
+# ARMV7_SUPPORTS_LARGE_PAGE_ADDRESSING
+# Defined if core supports the Large Page Addressing extension.
+
+ifeq ($(filter yes,$(ARM_CORTEX_A7) $(ARM_CORTEX_A12) $(ARM_CORTEX_A15) $(ARM_CORTEX_A17)),yes)
+$(eval $(call add_define,ARMV7_SUPPORTS_LARGE_PAGE_ADDRESSING))
+endif