[PATCH 1/3] kexec: introduce helpers for computing dtb size

[Wang Nan <wangnan0@huawei.com>]

This patch introduce fdt_node_len and fdt_prop_len to help for computing
memory requirement when operating dtb.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Dave Young <dyoung@redhat.com>
Cc: Geng Hui <hui.geng@huawei.com>
---
 kexec/libfdt/libfdt.h          | 24 ++++++++++++++++++++++++
 kexec/libfdt/libfdt_internal.h |  3 ---
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/kexec/libfdt/libfdt.h b/kexec/libfdt/libfdt.h
index ce80e4f..87a24ab 100644
--- a/kexec/libfdt/libfdt.h
+++ b/kexec/libfdt/libfdt.h
@@ -1073,4 +1073,28 @@ int fdt_del_node(void *fdt, int nodeoffset);
 
 const char *fdt_strerror(int errval);
 
+#define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
+#define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
+
+/*
+ * if add a new subnode:
+ * see: fdt_add_subnode -> fdt_add_subnode_namelen
+ */
+static inline int fdt_node_len(const char* node_name)
+{
+	return sizeof(struct fdt_node_header) +
+		FDT_TAGALIGN(strlen(node_name) + 1) + FDT_TAGSIZE;
+}
+
+/*
+ * if add a new prop: (assume prop_name not exist in strtab)
+ * see: fdt_setprop -> _fdt_add_property
+ */
+static inline int fdt_prop_len(const char* prop_name, int len)
+{
+	return (strlen(prop_name) + 1) +
+		sizeof(struct fdt_property) +
+		FDT_TAGALIGN(len);
+}
+
 #endif /* _LIBFDT_H */
diff --git a/kexec/libfdt/libfdt_internal.h b/kexec/libfdt/libfdt_internal.h
index 46eb93e..7e6c4c8 100644
--- a/kexec/libfdt/libfdt_internal.h
+++ b/kexec/libfdt/libfdt_internal.h
@@ -52,9 +52,6 @@
  */
 #include <fdt.h>
 
-#define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
-#define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
-
 #define FDT_CHECK_HEADER(fdt) \
 	{ \
 		int err; \
-- 
1.8.4


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