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

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