of/flattree: Refactor unflatten_device_tree and add fdt_unflatten_tree

unflatten_device_tree has two dependencies on things that happen
during boot time.  Firstly, it references the initial device tree
directly. Secondly, it allocates memory using the early boot
allocator.  This patch factors out these dependencies and uses
the new __unflatten_device_tree function to implement a driver-visible
fdt_unflatten_tree function, which can be used to unflatten a
blob after boot time.

V2:
- remove extra __va() call
- make dt_alloc functions return void *.  This doesn't fix the general
  strangeness in this code that constantly casts back and forth between
  unsigned long and __be32 *

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 70c5b736f0a3..9ce5dfd2186a 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -68,6 +68,8 @@ extern void *of_fdt_get_property(struct boot_param_header *blob,
 extern int of_fdt_is_compatible(struct boot_param_header *blob,
 				unsigned long node,
 				const char *compat);
+extern void of_fdt_unflatten_tree(unsigned long *blob,
+			       struct device_node **mynodes);
 
 /* TBD: Temporary export of fdt globals - remove when code fully merged */
 extern int __initdata dt_root_addr_cells;