of/flattree: Make the kernel accept ePAPR style phandle information

Currently when processing flattened device trees, the kernel expects
the phandle in a property called "linux,phandle".  The ePAPR spec -
not being Linux specific - instead requires phandles to be encoded in
a property named simply "phandle".  This patch makes the kernel accept
either form when unflattening the device tree.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 18d282fefe58..b51f797d9d9d 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -310,10 +310,19 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
                                         __alignof__(struct property));
                 if (allnextpp) {
-                        if (strcmp(pname, "linux,phandle") == 0) {
+                        /* We accept flattened tree phandles either in
+                         * ePAPR-style "phandle" properties, or the
+                         * legacy "linux,phandle" properties.  If both
+                         * appear and have different values, things
+                         * will get weird.  Don't do that. */
+                        if ((strcmp(pname, "phandle") == 0) ||
+                            (strcmp(pname, "linux,phandle") == 0)) {
                                 if (np->phandle == 0)
                                         np->phandle = *((u32 *)*p);
                         }
+                        /* And we process the "ibm,phandle" property
+                         * used in pSeries dynamic device tree
+                         * stuff */
                         if (strcmp(pname, "ibm,phandle") == 0)
                                 np->phandle = *((u32 *)*p);
                         pp->name = pname;