t210: Move page tables to end of TZDRAM

BL31 makes an assumption that TZDRAM always starts at its base. This
was not true in our case since coreboot page tables were located
towards the start of TZDRAM. Instead move page tables to the end, thus
satisfying the assumption that BL31 base is the base of TZDRAM as
well.

BUG=chrome-os-partner:42989
BRANCH=None
TEST=Compiles successfully and boots to kernel prompt

Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Original-Commit-Id: aabed336da6e9aea426650c5ca5977ccfc83a21b
Original-Change-Id: Ic4d155525dbb4baab95c971f77848e47d5d54dba
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/291020
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Original-Trybot-Ready: Furquan Shaikh <furquan@chromium.org>
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-(cherry picked from commit a57127f1655ef311b82c41ce33ffc71db5f9db35)
Original-Reviewed-on: https://chromium-review.googlesource.com/290987

Change-Id: Ie7166fd0301b46eb32f44107f7f782c6d79a278c
Reviewed-on: http://review.coreboot.org/11383
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

2 files changed, 35 insertions, 9 deletions

diff --git a/src/soc/nvidia/tegra210/Makefile.inc b/src/soc/nvidia/tegra210/Makefile.inc
index 0593f06e52..fb38d38409 100644
--- a/src/soc/nvidia/tegra210/Makefile.inc
+++ b/src/soc/nvidia/tegra210/Makefile.inc
@@ -161,14 +161,11 @@ endif
 
 # BL31 component is placed towards the end of 32-bit address space. This assumes
 # that TrustZone memory is placed at the end of 32-bit address space. Within the
-# TZ memory, we place TTB at the beginning and then remaining space can be used
-# up by BL31 and secure OS. Calculate TZDRAM_BASE i.e. base of BL31 component
-# by:
+# TZ memory, we place BL31 and BL32(if available) towards the beginning and TTB
+# towards the end. Calculate TZDRAM_BASE i.e. base of BL31 component by:
 #   0x1000 = end of 32-bit address space in MiB
 #   0x1000 - $(CONFIG_TRUSTZONE_CARVEOUT_SIZE_MB) = start of TZ memory in MiB
-#   0x1000 - $(CONFIG_TRUSTZONE_CARVEOUT_SIZE_MB) + $(CONFIG_TTB_SIZE_MB)
-#             = skip TTB buffer and get base address of BL31
-BL31_MAKEARGS += TZDRAM_BASE=$$(((0x1000 - $(CONFIG_TRUSTZONE_CARVEOUT_SIZE_MB) + $(CONFIG_TTB_SIZE_MB)) << 20))
+BL31_MAKEARGS += TZDRAM_BASE=$$(((0x1000 - $(CONFIG_TRUSTZONE_CARVEOUT_SIZE_MB)) << 20))
 BL31_MAKEARGS += PLAT=tegra TARGET_SOC=t210
 
 # MTC fw
diff --git a/src/soc/nvidia/tegra210/mmu_operations.c b/src/soc/nvidia/tegra210/mmu_operations.c
index dd7437c3d7..5578933514 100644
--- a/src/soc/nvidia/tegra210/mmu_operations.c
+++ b/src/soc/nvidia/tegra210/mmu_operations.c
@@ -18,6 +18,7 @@
  */
 
 #include <arch/mmu.h>
+#include <assert.h>
 #include <memrange.h>
 #include <soc/addressmap.h>
 #include <soc/mmu_operations.h>
@@ -69,15 +70,43 @@ void tegra210_mmu_init(void)
 {
 	uintptr_t tz_base_mib;
 	size_t tz_size_mib;
+	uintptr_t ttb_base_mib;
 	size_t ttb_size_mib;
 	struct memranges *map = &t210_mmap_ranges;
 
 	tegra210_memrange_init(map);
 	mainboard_add_memory_ranges(map);
-	/* Place page tables at the base of the trust zone region. */
+	/*
+	 * Place page tables at the end of the trust zone region.
+	 * TZDRAM layout is as follows:
+	 *
+	 * +--------------------------+ <----+DRAM_END
+	 * |                          |
+	 * |                          |
+	 * |                          |
+	 * +--------------------------+ <----+0x100000000
+	 * |                          |
+	 * |   coreboot page tables   |
+	 * +--------------------------+
+	 * |                          |
+	 * |        BL32              |
+	 * +--------------------------+
+	 * |                          |
+	 * |        BL31              |
+	 * +--------------------------+ <----+TZDRAM_BASE
+	 * |                          |
+	 * |                          |
+	 * |                          |
+	 * |                          |
+	 * +--------------------------+ <----+DRAM_BASE
+	 *
+	 */
 	carveout_range(CARVEOUT_TZ, &tz_base_mib, &tz_size_mib);
-	tz_base_mib *= MiB;
+
+	assert(tz_size_mib > CONFIG_TTB_SIZE_MB);
+	ttb_base_mib = (tz_base_mib + tz_size_mib - CONFIG_TTB_SIZE_MB) * MiB;
+
 	ttb_size_mib = CONFIG_TTB_SIZE_MB * MiB;
-	mmu_init(map, (void *)tz_base_mib, ttb_size_mib);
+	mmu_init(map, (void *)ttb_base_mib, ttb_size_mib);
 	mmu_enable();
 }