Merge changes from topic "refactor_prepare_dtb" into integration

* changes:
  refactor(zynqmp): use common code for prepare_dtb
  refactor(xilinx): remove multiple return paths in prepare_dtb
diff --git a/plat/xilinx/common/plat_fdt.c b/plat/xilinx/common/plat_fdt.c
index 911f664..de5d1a1 100644
--- a/plat/xilinx/common/plat_fdt.c
+++ b/plat/xilinx/common/plat_fdt.c
@@ -15,61 +15,84 @@
 
 void prepare_dtb(void)
 {
+#if defined(XILINX_OF_BOARD_DTB_ADDR)
 	void *dtb;
-	int ret;
-#if !defined(XILINX_OF_BOARD_DTB_ADDR)
-	return;
-#else
+	int map_ret = 0;
+	int ret = 0;
+
 	dtb = (void *)XILINX_OF_BOARD_DTB_ADDR;
-#endif
-	if (IS_TFA_IN_OCM(BL31_BASE))
-		return;
+
+	if (!IS_TFA_IN_OCM(BL31_BASE)) {
 
 #if defined(PLAT_XLAT_TABLES_DYNAMIC)
-	ret = mmap_add_dynamic_region((unsigned long long)dtb,
-				      (uintptr_t)dtb,
-				      XILINX_OF_BOARD_DTB_MAX_SIZE,
-				      MT_MEMORY | MT_RW | MT_NS);
-	if (ret != 0) {
-		WARN("Failed to add dynamic region for dtb: error %d\n", ret);
-		return;
-	}
+		map_ret = mmap_add_dynamic_region((unsigned long long)dtb,
+						 (uintptr_t)dtb,
+						 XILINX_OF_BOARD_DTB_MAX_SIZE,
+						 MT_MEMORY | MT_RW | MT_NS);
+		if (map_ret != 0) {
+			WARN("Failed to add dynamic region for dtb: error %d\n",
+			     map_ret);
+		}
 #endif
 
-	/* Return if no device tree is detected */
-	if (fdt_check_header(dtb) != 0) {
-		NOTICE("Can't read DT at %p\n", dtb);
-		return;
-	}
+		if (!map_ret) {
+			/* Return if no device tree is detected */
+			if (fdt_check_header(dtb) != 0) {
+				NOTICE("Can't read DT at %p\n", dtb);
+			} else {
+				ret = fdt_open_into(dtb, dtb, XILINX_OF_BOARD_DTB_MAX_SIZE);
 
-	ret = fdt_open_into(dtb, dtb, XILINX_OF_BOARD_DTB_MAX_SIZE);
-	if (ret < 0) {
-		ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
-		return;
-	}
+				if (ret < 0) {
+					ERROR("Invalid Device Tree at %p: error %d\n",
+					      dtb, ret);
+				} else {
 
-	/* Reserve memory used by Trusted Firmware. */
-	if (fdt_add_reserved_memory(dtb, "tf-a", BL31_BASE, BL31_LIMIT - BL31_BASE)) {
-		WARN("Failed to add reserved memory nodes for BL31 to DT.\n");
-		return;
-	}
+					if (dt_add_psci_node(dtb)) {
+						WARN("Failed to add PSCI Device Tree node\n");
+					}
 
-	ret = fdt_pack(dtb);
-	if (ret < 0) {
-		ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
-		return;
-	}
+					if (dt_add_psci_cpu_enable_methods(dtb)) {
+						WARN("Failed to add PSCI cpu enable methods in DT\n");
+					}
 
-	flush_dcache_range((uintptr_t)dtb, fdt_blob_size(dtb));
+					/* Reserve memory used by Trusted Firmware. */
+					ret = fdt_add_reserved_memory(dtb,
+								     "tf-a",
+								     BL31_BASE,
+								     BL31_LIMIT
+								     -
+								     BL31_BASE);
+					if (ret < 0) {
+						WARN("Failed to add reserved memory nodes for BL31 to DT.\n");
+					}
+
+					ret = fdt_pack(dtb);
+					if (ret < 0) {
+						WARN("Failed to pack dtb at %p: error %d\n",
+						     dtb, ret);
+					}
+					flush_dcache_range((uintptr_t)dtb,
+							   fdt_blob_size(dtb));
+
+					INFO("Changed device tree to advertise PSCI and reserved memories.\n");
+
+				}
+			}
+
+		}
+
 
 #if defined(PLAT_XLAT_TABLES_DYNAMIC)
-	ret = mmap_remove_dynamic_region((uintptr_t)dtb,
+		if (!map_ret) {
+			ret = mmap_remove_dynamic_region((uintptr_t)dtb,
 					 XILINX_OF_BOARD_DTB_MAX_SIZE);
-	if (ret != 0) {
-		WARN("Failed to remove dynamic region for dtb: error %d\n", ret);
-		return;
-	}
+			if (ret != 0) {
+				WARN("Failed to remove dynamic region for dtb:error %d\n",
+					ret);
+			}
+		}
 #endif
+	}
 
-	INFO("Changed device tree to advertise PSCI and reserved memories.\n");
+#endif
 }
diff --git a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
index 7bdaf18..32bb982 100644
--- a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
+++ b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
@@ -21,6 +21,7 @@
 #include <plat/common/platform.h>
 
 #include <custom_svc.h>
+#include <plat_fdt.h>
 #include <plat_private.h>
 #include <plat_startup.h>
 #include <zynqmp_def.h>
@@ -183,55 +184,9 @@
 }
 #endif
 
-#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;
-	int ret;
-
-	/* Return if no device tree is detected */
-	if (fdt_check_header(dtb) != 0) {
-		NOTICE("Can't read DT at %p\n", dtb);
-		return;
-	}
-
-	ret = fdt_open_into(dtb, dtb, XILINX_OF_BOARD_DTB_MAX_SIZE);
-	if (ret < 0) {
-		ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
-		return;
-	}
-
-	if (dt_add_psci_node(dtb)) {
-		ERROR("Failed to add PSCI Device Tree node\n");
-		return;
-	}
-
-	if (dt_add_psci_cpu_enable_methods(dtb)) {
-		ERROR("Failed to add PSCI cpu enable methods in Device Tree\n");
-		return;
-	}
-
-	/* Reserve memory used by Trusted Firmware. */
-	if (fdt_add_reserved_memory(dtb, "tf-a", BL31_BASE,
-				   (size_t) (BL31_LIMIT - BL31_BASE))) {
-		WARN("Failed to add reserved memory nodes for BL31 to DT.\n");
-	}
-
-	ret = fdt_pack(dtb);
-	if (ret < 0) {
-		ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
-	}
-
-	clean_dcache_range((uintptr_t)dtb, fdt_blob_size(dtb));
-	INFO("Changed device tree to advertise PSCI and reserved memories.\n");
-}
-#endif
-
 void bl31_platform_setup(void)
 {
-#if (defined(XILINX_OF_BOARD_DTB_ADDR) && !IS_TFA_IN_OCM(BL31_BASE))
 	prepare_dtb();
-#endif
 
 	/* Initialize the gic cpu and distributor interfaces */
 	plat_arm_gic_driver_init();
diff --git a/plat/xilinx/zynqmp/platform.mk b/plat/xilinx/zynqmp/platform.mk
index 9c79855..e20cb22 100644
--- a/plat/xilinx/zynqmp/platform.mk
+++ b/plat/xilinx/zynqmp/platform.mk
@@ -127,6 +127,7 @@
 				${LIBFDT_SRCS}					\
 				plat/xilinx/common/ipi_mailbox_service/ipi_mailbox_svc.c \
 				plat/xilinx/common/plat_startup.c		\
+				plat/xilinx/common/plat_fdt.c			\
 				plat/xilinx/zynqmp/bl31_zynqmp_setup.c		\
 				plat/xilinx/zynqmp/plat_psci.c			\
 				plat/xilinx/zynqmp/plat_zynqmp.c		\