libfdt: Several cleanups to parameter checking

This patch makes a couple of small cleanups to parameter checking of
libfdt functions.

	- In several functions which take a node offset, we use an
idiom involving fdt_next_tag() first to check that we have indeed been
given a node offset.  This patch adds a helper function
_fdt_check_node_offset() to encapsulate this usage of fdt_next_tag().

	- In fdt_rw.c in several places we have the expanded version
of the RW_CHECK_HEADER() macro for no particular reason.  This patch
replaces those instances with an invocation of the macro; that's what
it's for.

	- In fdt_sw.c we rename the check_header_sw() function to
sw_check_header() to match the analgous function in fdt_rw.c, and we
provide an SW_CHECK_HEADER() wrapper macro as RW_CHECK_HEADER()
functions in fdt_rw.c

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 15 insertions, 16 deletions

diff --git a/libfdt/fdt_sw.c b/libfdt/fdt_sw.c
index dda2de34b..df0987606 100644
--- a/libfdt/fdt_sw.c
+++ b/libfdt/fdt_sw.c
@@ -55,13 +55,21 @@
 
 #include "libfdt_internal.h"
 
-static int check_header_sw(void *fdt)
+static int sw_check_header(void *fdt)
 {
 	if (fdt_magic(fdt) != SW_MAGIC)
 		return -FDT_ERR_BADMAGIC;
+	/* FIXME: should check more details about the header state */
 	return 0;
 }
 
+#define SW_CHECK_HEADER(fdt) \
+	{ \
+		int err; \
+		if ((err = sw_check_header(fdt)) != 0) \
+			return err; \
+	}
+
 static void *grab_space(void *fdt, int len)
 {
 	int offset = fdt_size_dt_struct(fdt);
@@ -102,11 +110,10 @@ int fdt_create(void *buf, int bufsize)
 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 {
 	struct fdt_reserve_entry *re;
-	int err = check_header_sw(fdt);
 	int offset;
 
-	if (err)
-		return err;
+	SW_CHECK_HEADER(fdt);
+
 	if (fdt_size_dt_struct(fdt))
 		return -FDT_ERR_BADSTATE;
 
@@ -131,11 +138,9 @@ int fdt_finish_reservemap(void *fdt)
 int fdt_begin_node(void *fdt, const char *name)
 {
 	struct fdt_node_header *nh;
-	int err = check_header_sw(fdt);
 	int namelen = strlen(name) + 1;
 
-	if (err)
-		return err;
+	SW_CHECK_HEADER(fdt);
 
 	nh = grab_space(fdt, sizeof(*nh) + ALIGN(namelen, FDT_TAGSIZE));
 	if (! nh)
@@ -149,10 +154,8 @@ int fdt_begin_node(void *fdt, const char *name)
 int fdt_end_node(void *fdt)
 {
 	uint32_t *en;
-	int err = check_header_sw(fdt);
 
-	if (err)
-		return err;
+	SW_CHECK_HEADER(fdt);
 
 	en = grab_space(fdt, FDT_TAGSIZE);
 	if (! en)
@@ -188,11 +191,9 @@ static int find_add_string(void *fdt, const char *s)
 int fdt_property(void *fdt, const char *name, const void *val, int len)
 {
 	struct fdt_property *prop;
-	int err = check_header_sw(fdt);
 	int nameoff;
 
-	if (err)
-		return err;
+	SW_CHECK_HEADER(fdt);
 
 	nameoff = find_add_string(fdt, name);
 	if (nameoff == 0)
@@ -211,15 +212,13 @@ int fdt_property(void *fdt, const char *name, const void *val, int len)
 
 int fdt_finish(void *fdt)
 {
-	int err = check_header_sw(fdt);
 	char *p = (char *)fdt;
 	uint32_t *end;
 	int oldstroffset, newstroffset;
 	uint32_t tag;
 	int offset, nextoffset;
 
-	if (err)
-		return err;
+	SW_CHECK_HEADER(fdt);
 
 	/* Add terminator */
 	end = grab_space(fdt, sizeof(*end));