ppc440 caches - change proposal [RFC]

[Josh Boyer]

On Tue, 8 Apr 2008 17:15:44 -0600
"Grant Likely" <grant.likely at secretlab.ca> wrote:

> On Tue, Apr 8, 2008 at 4:56 PM, Benjamin Herrenschmidt
> <benh at kernel.crashing.org> wrote:
> >
> >  On Tue, 2008-04-08 at 15:53 -0700, John Bonesio wrote:
> >  > I was thinking it might be good to have the kernel initialize these
> >  > cache control registers in it's own start up code. Or perhaps this
> >  > could be done in the kernel's simple bootloader. We could probably put
> >  > this change in a Xilinx specific startup file, but this change doesn't
> >  > seem specific to Xilinx FPGA boards.
> >
> >  The kernel's wrapper would be a good place to put that I suspect. That's
> >  the kind of thing that should be provided as a "library" function to be
> >  optionally called by platform code. Either in the wrapper or the main
> >  kernel platform code.
> 
> Code is already queued up for 2.6.26 to do exactly this on ppc405
> virtex platforms.  We can do the same thing for 440.  Look at
> virtex405-head.S in the following patch:
> 
> http://patchwork.ozlabs.org/linuxppc/patch?person=486&id=17410

That patch is already in Paul's tree btw.

As for 440, yes it might be good to init the cache registers in the
wrapper.

josh