Re: [PATCH] enable RTAS /proc for PowerPC/CHRP platform

Arnd Bergmann wrote:

On Tuesday 17 October 2006 15:22, Christoph Hellwig wrote:

quoted

quoted

      rtas_node = of_find_node_by_name(NULL, "rtas");
      if (rtas_node == NULL)
              return -ENODEV;

And given this check I wonder why we need the platform check at all.  It
should be safe to just remove it.

One difference would be that it triggers on machines running SLOF (QS20, some JS20/JS21) and maybe some older Macs, which is probably a good
thing.

I wonder if it should be a little stricter though:

quoted

    rtas_node = of_find_node_by_path("/rtas");
    if (!rtas_node)
        return -ENODEV;

In case there is a node called "rtas" somewhere else.

    Arnd <><

Maybe we could check for the RTAS revision. The CHRP manual define this properties 'rtas-version' in /rtas/. This should be 1 for current implementation.

You can find here a new patch. It does not create the /proc/rtas and the symlink /proc/ppc64/rtas in  arch/powerpc/kernel/proc_ppc64.c anymore but rather create the entry (/proc/rtas) in arch/powerpc/kernel/rtas-proc.c and only the ppc64/ratas link for 64bit machine.

This has been tested on our PowerPC 32bit machine. It would be nice if PowerPC64 developer could reveiw and test it.

I stay ready to test upcomming patch if required.

Regards