of/fdt: create common debugfs

Both powerpc and microblaze have the same FDT blob in debugfs feature.
Move this to common location and remove the powerpc and microblaze
implementations. This feature could become more useful when FDT
overlay support is added.

This changes the path of the blob from "$arch/flat-device-tree" to
"device-tree/flat-device-tree".

Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Tested-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Stephen Chivers <schivers@csc.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: b0a6fb36a49f720c93c3da0b3f040e49e42435ad
[joonwoop@codeaurora.org: fixed trivial merge conflict.]
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>

arch/microblaze/kernel/prom.c

@@ -163,4 +163,3 @@ static int __init export_flat_device_tree(void)
 	return 0;
 }
 device_initcall(export_flat_device_tree);
-#endif

arch/powerpc/kernel/prom.c

@@ -29,7 +29,6 @@
 #include <linux/bitops.h>
 #include <linux/export.h>
 #include <linux/kexec.h>
-#include <linux/debugfs.h>
 #include <linux/irq.h>
 #include <linux/memblock.h>
 #include <linux/of.h>

drivers/of/fdt.c

@@ -20,6 +20,7 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/libfdt.h>
+#include <linux/debugfs.h>
 
 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
 #include <asm/page.h>
@@ -932,4 +933,27 @@ void __init unflatten_and_copy_device_tree(void)
 	unflatten_device_tree();
 }
 
+#if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
+static struct debugfs_blob_wrapper flat_dt_blob;
+
+static int __init of_flat_dt_debugfs_export_fdt(void)
+{
+	struct dentry *d = debugfs_create_dir("device-tree", NULL);
+
+	if (!d)
+		return -ENOENT;
+
+	flat_dt_blob.data = initial_boot_params;
+	flat_dt_blob.size = fdt_totalsize(initial_boot_params);
+
+	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
+				d, &flat_dt_blob);
+	if (!d)
+		return -ENOENT;
+
+	return 0;
+}
+module_init(of_flat_dt_debugfs_export_fdt);
+#endif
+
 #endif /* CONFIG_OF_EARLY_FLATTREE */