[PATCH V1 XRT Alveo Infrastructure 3/9] of: handle fdt buffer alignment inside unflatten function

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Add alignment check to of_fdt_unflatten_tree(). If it is not aligned,
allocate a aligned buffer and copy the fdt blob. So the caller does not
have to deal with the buffer alignment before calling this function.
XRT uses this function to unflatten fdt which is from Alveo firmware.

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
---
 drivers/of/fdt.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 4546572af24b..d64445e43ceb 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -455,13 +455,28 @@ void *of_fdt_unflatten_tree(const unsigned long *blob,
 			    struct device_node *dad,
 			    struct device_node **mynodes)
 {
+	void *new_fdt = NULL, *fdt_align;
 	void *mem;
 
+	if (fdt_check_header(blob)) {
+		pr_err("Invalid fdt blob\n");
+		return NULL;
+	}
+	fdt_align = (void *)PTR_ALIGN(blob, FDT_ALIGN_SIZE);
+	if (fdt_align != blob) {
+		new_fdt = kmalloc(fdt_totalsize(blob) + FDT_ALIGN_SIZE, GFP_KERNEL);
+		if (!new_fdt)
+			return NULL;
+		fdt_align = PTR_ALIGN(new_fdt, FDT_ALIGN_SIZE);
+	}
+
 	mutex_lock(&of_fdt_unflatten_mutex);
-	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
+	mem = __unflatten_device_tree(fdt_align, dad, mynodes, &kernel_tree_alloc,
 				      true);
 	mutex_unlock(&of_fdt_unflatten_mutex);
 
+	kfree(new_fdt);
+
 	return mem;
 }
 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
-- 
2.27.0




[Index of Archives]     [LM Sensors]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux