libfdt: Use void * to refer to device tree blobs
At present, the blob containing a device tree is passed to the various
fdt_*() functions as a (struct fdt_header *) i.e. a pointer to the
header structure at the beginning of the blob.
This patch changes all the functions so that they instead take a (void
*) pointing to the blob. Under some circumstances can avoid the need
for the caller to cast a blob pointer into a (struct fdt_header *)
before passing it to the fdt_*() functions.
Using a (void *) also reduce the temptation for users of the library
to directly dereference toe (struct fdt_header *) to access header
fields. Instead they must use the fdt_get_header() or
fdt_set_header() macros, or the fdt_magic(), fdt_totalsize()
etc. wrappers around them which are safer, since they will always
handle endian conversion.
With this change, the whole-tree moving, or manipulating functions:
fdt_move(), fdt_open_into() and fdt_pack() no longer need to return a
pointer to the "new" tree. The given (void *) buffer pointer they
take can instead be used directly by the caller as the new tree.
Those functions are thus changed to instead return an error code
(which in turn reduces the number of functions using the ugly encoding
of error values into pointers).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/fdt_rw.c b/fdt_rw.c
index 8049205..4b7d1d5 100644
--- a/fdt_rw.c
+++ b/fdt_rw.c
@@ -23,7 +23,7 @@
#include "libfdt_internal.h"
-static int rw_check_header(struct fdt_header *fdt)
+static int rw_check_header(void *fdt)
{
int err;
@@ -31,7 +31,7 @@
return err;
if (fdt_version(fdt) < 0x11)
return FDT_ERR_BADVERSION;
- if (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(*fdt), 8))
+ if (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(struct fdt_header), 8))
return FDT_ERR_BADLAYOUT;
if (fdt_off_dt_struct(fdt) <
(fdt_off_mem_rsvmap(fdt) + sizeof(struct fdt_reserve_entry)))
@@ -52,25 +52,24 @@
return OFFSET_ERROR(err); \
}
-static inline int _blob_data_size(struct fdt_header *fdt)
+static inline int _blob_data_size(void *fdt)
{
return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
}
-static int _blob_splice(struct fdt_header *fdt, void *p, int oldlen, int newlen)
+static int _blob_splice(void *fdt, void *p, int oldlen, int newlen)
{
- void *blob = fdt;
- void *end = blob + _blob_data_size(fdt);
+ void *end = fdt + _blob_data_size(fdt);
if (((p + oldlen) < p) || ((p + oldlen) > end))
return FDT_ERR_BADOFFSET;
- if ((end - oldlen + newlen) > (blob + fdt_totalsize(fdt)))
+ if ((end - oldlen + newlen) > (fdt + fdt_totalsize(fdt)))
return FDT_ERR_NOSPACE;
memmove(p + newlen, p + oldlen, end - p - oldlen);
return 0;
}
-static int _blob_splice_struct(struct fdt_header *fdt, void *p,
+static int _blob_splice_struct(void *fdt, void *p,
int oldlen, int newlen)
{
int delta = newlen - oldlen;
@@ -79,25 +78,24 @@
if ((err = _blob_splice(fdt, p, oldlen, newlen)))
return err;
- fdt->size_dt_struct = cpu_to_fdt32(fdt_size_dt_struct(fdt) + delta);
- fdt->off_dt_strings = cpu_to_fdt32(fdt_off_dt_strings(fdt) + delta);
+ fdt_set_header(fdt, size_dt_struct, fdt_size_dt_struct(fdt) + delta);
+ fdt_set_header(fdt, off_dt_strings, fdt_off_dt_strings(fdt) + delta);
return 0;
}
-static int _blob_splice_string(struct fdt_header *fdt, int newlen)
+static int _blob_splice_string(void *fdt, int newlen)
{
- void *blob = fdt;
- void *p = blob + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
+ void *p = fdt + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
int err;
if ((err = _blob_splice(fdt, p, 0, newlen)))
return err;
- fdt->size_dt_strings = cpu_to_fdt32(fdt_size_dt_strings(fdt) + newlen);
+ fdt_set_header(fdt, size_dt_strings, fdt_size_dt_strings(fdt) + newlen);
return 0;
}
-static int _find_add_string(struct fdt_header *fdt, const char *s)
+static int _find_add_string(void *fdt, const char *s)
{
char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
const char *p;
@@ -119,7 +117,7 @@
return (new - strtab);
}
-static struct fdt_property *_resize_property(struct fdt_header *fdt, int nodeoffset,
+static struct fdt_property *_resize_property(void *fdt, int nodeoffset,
const char *name, int len)
{
struct fdt_property *prop;
@@ -139,7 +137,7 @@
return prop;
}
-static struct fdt_property *_add_property(struct fdt_header *fdt, int nodeoffset,
+static struct fdt_property *_add_property(void *fdt, int nodeoffset,
const char *name, int len)
{
uint32_t tag;
@@ -170,7 +168,7 @@
return prop;
}
-int fdt_setprop(struct fdt_header *fdt, int nodeoffset, const char *name,
+int fdt_setprop(void *fdt, int nodeoffset, const char *name,
const void *val, int len)
{
struct fdt_property *prop;
@@ -192,7 +190,7 @@
return 0;
}
-int fdt_delprop(struct fdt_header *fdt, int nodeoffset, const char *name)
+int fdt_delprop(void *fdt, int nodeoffset, const char *name)
{
struct fdt_property *prop;
int len, proplen;
@@ -208,7 +206,7 @@
return _blob_splice_struct(fdt, prop, proplen, 0);
}
-int fdt_add_subnode_namelen(struct fdt_header *fdt, int parentoffset,
+int fdt_add_subnode_namelen(void *fdt, int parentoffset,
const char *name, int namelen)
{
struct fdt_node_header *nh;
@@ -249,12 +247,12 @@
return offset;
}
-int fdt_add_subnode(struct fdt_header *fdt, int parentoffset, const char *name)
+int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
{
return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
}
-int fdt_del_node(struct fdt_header *fdt, int nodeoffset)
+int fdt_del_node(void *fdt, int nodeoffset)
{
int endoffset;
int err;
@@ -267,35 +265,36 @@
endoffset - nodeoffset, 0);
}
-struct fdt_header *fdt_open_into(struct fdt_header *fdt, void *buf, int bufsize)
+int fdt_open_into(void *fdt, void *buf, int bufsize)
{
int err;
- fdt = fdt_move(fdt, buf, bufsize);
- if ((err = fdt_ptr_error(fdt)))
- return PTR_ERROR(err);
+ err = fdt_move(fdt, buf, bufsize);
+ if (err)
+ return err;
- fdt->totalsize = cpu_to_fdt32(bufsize);
+ fdt = buf;
+
+ fdt_set_header(fdt, totalsize, bufsize);
/* FIXME: re-order if necessary */
err = rw_check_header(fdt);
if (err)
- return PTR_ERROR(err);
+ return err;
- return fdt;
+ return FDT_ERR_OK;
}
-struct fdt_header *fdt_pack(struct fdt_header *fdt)
+int fdt_pack(void *fdt)
{
int err;
err = rw_check_header(fdt);
if (err)
- return PTR_ERROR(err);
+ return err;
/* FIXME: pack components */
-
- fdt->totalsize = cpu_to_fdt32(_blob_data_size(fdt));
- return fdt;
+ fdt_set_header(fdt, totalsize, _blob_data_size(fdt));
+ return FDT_ERR_OK;
}