Re: [PATCH v6 40/42] drivers/of: Return allocated memory chunk from of_fdt_unflatten_tree()

This changes of_fdt_unflatten_tree() so that it returns the allocated
memory chunk for unflattened device-tree, which can be released once
it's obsoleted.

Signed-off-by: Gavin Shan <redacted>
---
 drivers/of/fdt.c       | 11 ++++++-----
 include/linux/of_fdt.h |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 074870a..8e1ba7e 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c

@@ -408,7 +408,7 @@ static void *unflatten_dt_node(const void *blob,
  * @dt_alloc: An allocator that provides a virtual address to memory
  * for the resulting tree
  */
-static void __unflatten_device_tree(const void *blob,
+static void *__unflatten_device_tree(const void *blob,
 			     struct device_node *dad,
 			     struct device_node **mynodes,
 			     void * (*dt_alloc)(u64 size, u64 align))

@@ -421,7 +421,7 @@ static void __unflatten_device_tree(const void *blob,
 
 	if (!blob) {
 		pr_debug("No device tree pointer\n");
-		return;
+		return NULL;
 	}
 
 	pr_debug("Unflattening device tree:\n");

@@ -431,7 +431,7 @@ static void __unflatten_device_tree(const void *blob,
 
 	if (fdt_check_header(blob)) {
 		pr_err("Invalid device tree blob header\n");
-		return;
+		return NULL;
 	}
 
 	/* First pass, scan for size */

@@ -458,6 +458,7 @@ static void __unflatten_device_tree(const void *blob,
 			   be32_to_cpup(mem + size));
 
 	pr_debug(" <- unflatten_device_tree()\n");
+	return mem;
 }
 
 static void *kernel_tree_alloc(u64 size, u64 align)

@@ -473,11 +474,11 @@ static void *kernel_tree_alloc(u64 size, u64 align)
  * pointers of the nodes so the normal device-tree walking functions
  * can be used.
  */
-void of_fdt_unflatten_tree(const unsigned long *blob,
+void *of_fdt_unflatten_tree(const unsigned long *blob,

 			struct device_node *dad,
 			struct device_node **mynodes)
 {
-	__unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc);
+	return __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc);
 }
 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 

diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 3644960..00db279 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h

@@ -37,7 +37,7 @@ extern bool of_fdt_is_big_endian(const void *blob,
 				 unsigned long node);
 extern int of_fdt_match(const void *blob, unsigned long node,
 			const char *const *compat);
-extern void of_fdt_unflatten_tree(const unsigned long *blob,
+extern void *of_fdt_unflatten_tree(const unsigned long *blob,
 			       struct device_node *dad,
 			       struct device_node **mynodes);