Tegra: sanity check non-secure DRAM address

This patch fixes the logic to validate if a non-secure memory address
overlaps the TZDRAM memory aperture.

Change-Id: I68af7dc6acc705d7b0ee9161c4002376077b46b1
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -381,13 +381,15 @@ void bl31_plat_arch_setup(void)
  ******************************************************************************/
 int32_t bl31_check_ns_address(uint64_t base, uint64_t size_in_bytes)
 {
-	uint64_t end = base + size_in_bytes;
+	uint64_t end = base + size_in_bytes - U(1);
 	int32_t ret = 0;
 
 	/*
 	 * Check if the NS DRAM address is valid
 	 */
-	if ((base < TEGRA_DRAM_BASE) || (end > TEGRA_DRAM_END)) {
+	if ((base < TEGRA_DRAM_BASE) || (base >= TEGRA_DRAM_END) ||
+	    (end > TEGRA_DRAM_END)) {
+
 		ERROR("NS address is out-of-bounds!\n");
 		ret = -EFAULT;
 	}
@@ -396,7 +398,7 @@ int32_t bl31_check_ns_address(uint64_t base, uint64_t size_in_bytes)
 	 * TZDRAM aperture contains the BL31 and BL32 images, so we need
 	 * to check if the NS DRAM range overlaps the TZDRAM aperture.
 	 */
-	if ((base < TZDRAM_END) && (end > tegra_bl31_phys_base)) {
+	if ((base < (uint64_t)TZDRAM_END) && (end > tegra_bl31_phys_base)) {
 		ERROR("NS address overlaps TZDRAM!\n");
 		ret = -ENOTSUP;
 	}