Reserve a Video Memory aperture in DRAM memory
This patch adds support to reserve a memory carveout region in the
DRAM on Tegra SoCs. The memory controller provides specific registers
to specify the aperture's base and size. This aperture can also be
changed dynamically in order to re-size the memory available for
DRM video playback. In case of the new aperture not overlapping
the previous one, the previous aperture has to be cleared before
setting up the new one. This means we do not "leak" any video data
to the NS world.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/tegra_bl31_setup.c b/plat/nvidia/tegra/common/tegra_bl31_setup.c
index 628dc2a..d126501 100644
--- a/plat/nvidia/tegra/common/tegra_bl31_setup.c
+++ b/plat/nvidia/tegra/common/tegra_bl31_setup.c
@@ -37,6 +37,7 @@
#include <cortex_a57.h>
#include <cortex_a53.h>
#include <debug.h>
+#include <errno.h>
#include <memctrl.h>
#include <mmio.h>
#include <platform.h>
@@ -226,3 +227,32 @@
/* enable the MMU */
enable_mmu_el3(0);
}
+
+/*******************************************************************************
+ * Check if the given NS DRAM range is valid
+ ******************************************************************************/
+int bl31_check_ns_address(uint64_t base, uint64_t size_in_bytes)
+{
+ uint64_t end = base + size_in_bytes - 1;
+
+ /*
+ * Check if the NS DRAM address is valid
+ */
+ if ((base < TEGRA_DRAM_BASE) || (end > TEGRA_DRAM_END) ||
+ (base >= end)) {
+ ERROR("NS address is out-of-bounds!\n");
+ return -EFAULT;
+ }
+
+ /*
+ * 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)) {
+ ERROR("NS address overlaps TZDRAM!\n");
+ return -ENOTSUP;
+ }
+
+ /* valid NS address */
+ return 0;
+}