[SLOF] [PATCH v4] board-qemu: add private hcall to inform host on "phandle" update

Segher Boessenkool segher at kernel.crashing.org
Wed Sep 6 23:41:21 AEST 2017


On Wed, Sep 06, 2017 at 02:33:45PM +0200, Greg Kurz wrote:
> But David Gibson seems to be "really, really" opposed to this solution as
> expressed in this thread:
> 
> https://lists.nongnu.org/archive/html/qemu-ppc/2017-07/msg00556.html
> 
> He's asking if we can change SLOF to not use phandles as raw pointers
> instead... I must admit that this goes way beyond my very limited
> knowledge on SLOF and forth... :-\

A phandle is an opaque cookie to everything but the firmware itself.
Using pointers to some internal structure works just fine; most Open
Firmware implementations do this.

Anything other than OF itself should *not* make up phandles.  There
is no way to guarantee these will be unique, so it is a non-starter.

If QEMU wants to create a device node, it should ask OF to do it,
say, via new-device.


Segher


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