feat(fvp): add plat API to validate that passed region is non-secure

Added a platform function to check passed region is within
the Non-Secure region of DRAM.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: Ie5808fa6a1b6e6bc99f4185fa8acc52af0d5f14d

include/plat/common/plat_drtm.h

@@ -64,4 +64,11 @@ uint64_t plat_drtm_get_tcb_hash_features(void);
 int plat_set_drtm_error(uint64_t error_code);
 int plat_get_drtm_error(uint64_t *error_code);
 
+/*
+ * Platform-specific function to ensure passed region lies within
+ * Non-Secure region of DRAM
+ */
+int plat_drtm_validate_ns_region(uintptr_t region_start,
+				 size_t region_size);
+
 #endif /* PLAT_DRTM_H */

plat/arm/board/fvp/fvp_drtm_addr.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2022 Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier:    BSD-3-Clause
+ *
+ */
+
+#include <stdint.h>
+
+#include <plat/common/platform.h>
+#include <platform_def.h>
+
+/*******************************************************************************
+ * Check passed region is within Non-Secure region of DRAM
+ ******************************************************************************/
+int plat_drtm_validate_ns_region(uintptr_t region_start,
+				 size_t region_size)
+{
+	uintptr_t region_end = region_start + region_size - 1;
+
+	if (region_start >= region_end) {
+		return -1;
+	} else if ((region_start >= ARM_NS_DRAM1_BASE) &&
+		   (region_start < (ARM_NS_DRAM1_BASE + ARM_NS_DRAM1_SIZE)) &&
+		   (region_end >= ARM_NS_DRAM1_BASE) &&
+		   (region_end < (ARM_NS_DRAM1_BASE + ARM_NS_DRAM1_SIZE))) {
+		return 0;
+	} else if ((region_start >= ARM_DRAM2_BASE) &&
+		   (region_start < (ARM_DRAM2_BASE + ARM_DRAM2_SIZE)) &&
+		   (region_end >= ARM_DRAM2_BASE) &&
+		   (region_end < (ARM_DRAM2_BASE + ARM_DRAM2_SIZE))) {
+		return 0;
+	}
+
+	return -1;
+}