fix(zynqmp): conditional reservation of memory in DTB

When the TF-A is placed in DDR memory range, the DDR memory range is
getting explicitly reserved in the default device tree by TF-A.
This creates an error condition in the use case where Device tree is
not present or it is present at a different location.

To fix this, a new build time parameter, XILINX_OF_BOARD_DTB_ADDR, is
introduced. The TF-A will reserve the DDR memory only when a valid
DTB address is provided to XILINX_OF_BOARD_DTB_ADDR during build.

Now the user has options, either manually reserve the desired
DDR address range for TF-A in device tree or let TF-A access and modify
the device tree, to reserve the DDR address range, in runtime using
the build parameter.

Change-Id: I846fa373ba9f7c984eda3a55ccaaa622082cad81
Signed-off-by: Akshay Belsare <akshay.belsare@amd.com>

3 files changed, 17 insertions, 6 deletions

diff --git a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
index 1d963e82a..0ebd0885a 100644
--- a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
+++ b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
@@ -171,7 +171,7 @@ static uint64_t rdo_el3_interrupt_handler(uint32_t id, uint32_t flags,
 }
 #endif
 
-#if (BL31_LIMIT < PLAT_DDR_LOWMEM_MAX)
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
 static void prepare_dtb(void)
 {
 	void *dtb = (void *)XILINX_OF_BOARD_DTB_ADDR;
@@ -217,7 +217,7 @@ static void prepare_dtb(void)
 
 void bl31_platform_setup(void)
 {
-#if (BL31_LIMIT < PLAT_DDR_LOWMEM_MAX)
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
 	prepare_dtb();
 #endif
 
@@ -250,7 +250,7 @@ void bl31_plat_arch_setup(void)
 	plat_arm_interconnect_enter_coherency();
 
 	const mmap_region_t bl_regions[] = {
-#if (BL31_LIMIT < PLAT_DDR_LOWMEM_MAX)
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
 		MAP_REGION_FLAT(XILINX_OF_BOARD_DTB_ADDR, XILINX_OF_BOARD_DTB_MAX_SIZE,
 			MT_MEMORY | MT_RW | MT_NS),
 #endif
diff --git a/plat/xilinx/zynqmp/include/platform_def.h b/plat/xilinx/zynqmp/include/platform_def.h
index b46eb636e..aebce304e 100644
--- a/plat/xilinx/zynqmp/include/platform_def.h
+++ b/plat/xilinx/zynqmp/include/platform_def.h
@@ -1,5 +1,7 @@
 /*
  * Copyright (c) 2014-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2022, Xilinx, Inc. All rights reserved.
+ * Copyright (c) 2022-2023, Advanced Micro Devices, Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -83,15 +85,18 @@
 /*******************************************************************************
  * Platform specific page table and MMU setup constants
  ******************************************************************************/
-#define XILINX_OF_BOARD_DTB_ADDR	U(0x100000)
 #define XILINX_OF_BOARD_DTB_MAX_SIZE	U(0x200000)
 #define PLAT_DDR_LOWMEM_MAX		U(0x80000000)
+#define PLAT_OCM_BASE			U(0xFFFC0000)
+#define PLAT_OCM_LIMIT			U(0xFFFFFFFF)
+
+#define IS_TFA_IN_OCM(x)		((x >= PLAT_OCM_BASE) && (x < PLAT_OCM_LIMIT))
 
 #define PLAT_PHY_ADDR_SPACE_SIZE	(1ULL << 32)
 #define PLAT_VIRT_ADDR_SPACE_SIZE	(1ULL << 32)
 
 #ifndef MAX_MMAP_REGIONS
-#if (BL31_LIMIT < PLAT_DDR_LOWMEM_MAX)
+#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
 #define MAX_MMAP_REGIONS		8
 #else
 #define MAX_MMAP_REGIONS		7
@@ -99,7 +104,7 @@
 #endif
 
 #ifndef MAX_XLAT_TABLES
-#if (BL31_LIMIT < PLAT_DDR_LOWMEM_MAX)
+#if !IS_TFA_IN_OCM(BL31_BASE)
 #define MAX_XLAT_TABLES			8
 #else
 #define MAX_XLAT_TABLES			5
diff --git a/plat/xilinx/zynqmp/platform.mk b/plat/xilinx/zynqmp/platform.mk
index 38e740802..4671f5f11 100644
--- a/plat/xilinx/zynqmp/platform.mk
+++ b/plat/xilinx/zynqmp/platform.mk
@@ -1,6 +1,8 @@
 #
 # Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
 # Portions copyright (c) 2021-2022, ProvenRun S.A.S. All rights reserved.
+# Copyright (c) 2018-2022, Xilinx, Inc. All rights reserved.
+# Copyright (c) 2022-2023, Advanced Micro Devices, Inc. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
@@ -75,6 +77,10 @@ ifdef ZYNQMP_SECURE_EFUSES
     $(eval $(call add_define,ZYNQMP_SECURE_EFUSES))
 endif
 
+ifdef XILINX_OF_BOARD_DTB_ADDR
+$(eval $(call add_define,XILINX_OF_BOARD_DTB_ADDR))
+endif
+
 PLAT_INCLUDES		:=	-Iinclude/plat/arm/common/			\
 				-Iinclude/plat/arm/common/aarch64/		\
 				-Iplat/xilinx/common/include/			\