[PATCH v7 48/50] drivers/of: Return allocated memory from of_fdt_unflatten_tree()

Gavin Shan
2015-11-04T13:13:47Z

This returns the allocate memory chunk, storing the unflattened device
tree, from of_fdt_unflatten_tree() so that memory chunk can be released
on demand in PowerNV PCI hotplug driver.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Rob Herring <robh@kernel.org>
---
drivers/of/fdt.c | 25 ++++++++++++++++---------
include/linux/of_fdt.h | 6 +++---
2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 8c8228e..b0a5708 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -447,11 +447,14 @@ static void *unflatten_dt_nodes(const void *blob,
* @mynodes: The device_node tree created by the call
* @dt_alloc: An allocator that provides a virtual address to memory
* for the resulting tree
+ *
+ * Returns NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
*/
-static void __unflatten_device_tree(const void *blob,
- struct device_node *dad,
- struct device_node **mynodes,
- void * (*dt_alloc)(u64 size, u64 align))
+static void *__unflatten_device_tree(const void *blob,
+ struct device_node *dad,
+ struct device_node **mynodes,
+ void *(*dt_alloc)(u64 size, u64 align))
{
unsigned long size;
void *mem;
@@ -460,7 +463,7 @@ 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");
@@ -470,7 +473,7 @@ 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 */
@@ -494,6 +497,7 @@ 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)
@@ -511,10 +515,13 @@ static void *kernel_tree_alloc(u64 size, u64 align)
* tree of struct device_node. It also fills the "name" and "type"
* pointers of the nodes so the normal device-tree walking functions
* can be used.
+ *
+ * Returns NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
*/
-void of_fdt_unflatten_tree(const unsigned long *blob,
- struct device_node *dad,
- struct device_node **mynodes)
+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);
}
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 3644960..b87b26a7 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -37,9 +37,9 @@ 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,
- struct device_node *dad,
- struct device_node **mynodes);
+extern void *of_fdt_unflatten_tree(const unsigned long *blob,
+ struct device_node *dad,
+ struct device_node **mynodes);

/* TBD: Temporary export of fdt globals - remove when code fully merged */
extern int __initdata dt_root_addr_cells;
--
2.1.0