From b447242cd2457bec20d47fe6a8a5758d97a3bde3 Mon Sep 17 00:00:00 2001
From: Jaxson Han <jaxson.han@arm.com>
Date: Wed, 19 Jan 2022 16:19:02 +0800
Subject: [PATCH] common: Add mem usage to /memreserve/

Set /memreserve/ to prevent next boot stages from overrding PSCI
services with libfdt.

Issue-Id: SCM-3815
Upstream-Status: Inappropriate [other]
  Implementation pending further discussion
Signed-off-by: Jaxson Han <jaxson.han@arm.com>
Change-Id: I2ea80cdf736a910fa2c3deb622e21d50f04be960
---
 Makefile.am          |  2 +-
 common/boot.c        |  1 +
 common/device_tree.c | 34 ++++++++++++++++++++++++++++++++++
 include/boot.h       |  1 +
 4 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 common/device_tree.c

diff --git a/Makefile.am b/Makefile.am
index 5e8668a..734de92 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -34,7 +34,7 @@ endif
 PSCI_CPU_OFF	:= 0x84000002
 
 COMMON_SRC	:= common/
-COMMON_OBJ	:= boot.o bakery_lock.o platform.o lib.o
+COMMON_OBJ	:= boot.o bakery_lock.o platform.o lib.o device_tree.o
 
 LIBFDT_SRC	:= common/libfdt/
 LIBFDT_OBJS	:= fdt.o fdt_ro.o fdt_rw.o
diff --git a/common/boot.c b/common/boot.c
index c74d34c..ee2bea0 100644
--- a/common/boot.c
+++ b/common/boot.c
@@ -63,6 +63,7 @@ void __noreturn first_spin(unsigned int cpu, unsigned long *mbox,
 {
 	if (cpu == 0) {
 		init_platform();
+		dt_add_memreserve();
 
 		*mbox = (unsigned long)&entrypoint;
 		sevl();
diff --git a/common/device_tree.c b/common/device_tree.c
new file mode 100644
index 0000000..4d0876c
--- /dev/null
+++ b/common/device_tree.c
@@ -0,0 +1,34 @@
+/*
+ * device_tree.c - Basic device tree node handler
+ *
+ * Copyright (C) 2021 ARM Limited. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE.txt file.
+ */
+#include <libfdt.h>
+
+extern unsigned long dtb;
+extern char firmware_start[], firmware_end[];
+
+extern void print_string(const char *str);
+
+static void *blob;
+
+
+void dt_add_memreserve(void)
+{
+	int ret;
+
+	blob = (void*)&dtb;
+	print_string("Add /memreserve/\n\r");
+
+	fdt_open_into(blob, blob, fdt_totalsize(blob) +
+		      sizeof(struct fdt_reserve_entry));
+	ret = fdt_add_mem_rsv(blob, (uint64_t)firmware_start,
+			      (uint64_t)(firmware_end - firmware_start));
+
+	if(ret < 0) {
+		print_string("reserve mem add err\n\r");
+	}
+}
diff --git a/include/boot.h b/include/boot.h
index d75e013..c3e2ec1 100644
--- a/include/boot.h
+++ b/include/boot.h
@@ -16,4 +16,5 @@ void __noreturn spin(unsigned long *mbox, unsigned long invalid, int is_entry);
 void __noreturn first_spin(unsigned int cpu, unsigned long *mbox,
 			   unsigned long invalid_addr);
 
+void dt_add_memreserve(void);
 #endif