Make the kernel accept ePAPR style phandle information

Make the kernel accept ePAPR style phandle information

[David Gibson]

Grant, this is based on your test-devicetree branch, if it could be
merged via there would be great.

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-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>

Index: working-2.6/drivers/of/fdt.c
===================================================================
--- working-2.6.orig/drivers/of/fdt.c	2009-11-26 09:58:06.052792325 +1100
+++ working-2.6/drivers/of/fdt.c	2009-11-26 10:00:08.309570256 +1100
@@ -314,10 +314,19 @@ unsigned long __init unflatten_dt_node(u
 		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;


-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: Make the kernel accept ePAPR style phandle information

[Grant Likely]

On Wed, Nov 25, 2009 at 10:16 PM, David Gibson
<david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org> wrote:
> Grant, this is based on your test-devicetree branch, if it could be
> merged via there would be great.
>
> 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-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>

Looks okay to me.

g.

>
> Index: working-2.6/drivers/of/fdt.c
> ===================================================================
> --- working-2.6.orig/drivers/of/fdt.c   2009-11-26 09:58:06.052792325 +1100
> +++ working-2.6/drivers/of/fdt.c        2009-11-26 10:00:08.309570256 +1100
> @@ -314,10 +314,19 @@ unsigned long __init unflatten_dt_node(u
>                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;
>
>
> --
> David Gibson                    | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
>                                | _way_ _around_!
> http://www.ozlabs.org/~dgibson
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.