Tegra: memmap BL31's TZDRAM carveout

This patch maps the TZDRAM carveout used by the BL31. In the near
future BL31 would be running from the TZRAM for security and
performance reasons. The only downside to this solution is that
the TZRAM loses its state in System Suspend. So, we map the TZDRAM
carveout that the BL31 would use to save its state before entering
System Suspend.

Change-Id: Id5bda7e9864afd270cf86418c703fa61c2cb095f
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -225,6 +225,7 @@ void bl31_plat_arch_setup(void)
 #if USE_COHERENT_MEM
 	unsigned long coh_start, coh_size;
 #endif
+	plat_params_from_bl2_t *params_from_bl2 = bl31_get_plat_params();
 
 	/* add memory regions */
 	mmap_add_region(total_base, total_base,
@@ -234,6 +235,14 @@ void bl31_plat_arch_setup(void)
 			ro_size,
 			MT_MEMORY | MT_RO | MT_SECURE);
 
+	/* map TZDRAM used by BL31 as coherent memory */
+	if (TEGRA_TZRAM_BASE == tegra_bl31_phys_base) {
+		mmap_add_region(params_from_bl2->tzdram_base,
+				params_from_bl2->tzdram_base,
+				BL31_SIZE,
+				MT_DEVICE | MT_RW | MT_SECURE);
+	}
+
 #if USE_COHERENT_MEM
 	coh_start = total_base + (BL_COHERENT_RAM_BASE - BL31_RO_BASE);
 	coh_size = BL_COHERENT_RAM_END - BL_COHERENT_RAM_BASE;