of: use __be32 for cell value accessors

Currently, we're using u32 for cell values, and hence assuming
host-endian device trees.

As we'd like to support little-endian platforms, use a __be32 for cell
values, and convert in the cell accessors.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/of/fdt.c

@@ -431,9 +431,9 @@ int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 	return 1;
 }
 
-u64 __init dt_mem_next_cell(int s, u32 **cellp)
+u64 __init dt_mem_next_cell(int s, __be32 **cellp)
 {
-	u32 *p = *cellp;
+	__be32 *p = *cellp;
 
 	*cellp = p + s;
 	return of_read_number(p, s);

include/linux/of.h

@@ -20,6 +20,8 @@
 #include <linux/kref.h>
 #include <linux/mod_devicetable.h>
 
+#include <asm/byteorder.h>
+
 typedef u32 phandle;
 typedef u32 ihandle;
 
@@ -95,16 +97,16 @@ extern void of_node_put(struct device_node *node);
  */
 
 /* Helper to read a big number; size is in cells (not bytes) */
-static inline u64 of_read_number(const u32 *cell, int size)
+static inline u64 of_read_number(const __be32 *cell, int size)
 {
 	u64 r = 0;
 	while (size--)
-		r = (r << 32) | *(cell++);
+		r = (r << 32) | be32_to_cpu(*(cell++));
 	return r;
 }
 
 /* Like of_read_number, but we want an unsigned long result */
-static inline unsigned long of_read_ulong(const u32 *cell, int size)
+static inline unsigned long of_read_ulong(const __be32 *cell, int size)
 {
 	/* toss away upper bits if unsigned long is smaller than u64 */
 	return of_read_number(cell, size);

include/linux/of_fdt.h

@@ -78,7 +78,7 @@ extern void early_init_dt_check_for_initrd(unsigned long node);
 extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
 				     int depth, void *data);
 extern void early_init_dt_add_memory_arch(u64 base, u64 size);
-extern u64 dt_mem_next_cell(int s, u32 **cellp);
+extern u64 dt_mem_next_cell(int s, __be32 **cellp);
 
 /*
  * If BLK_DEV_INITRD, the fdt early init code will call this function,