[PATCH v2 13/31] arm64: Device specific operations

Olof Johansson olof at lixom.net
Sat Sep 15 20:28:16 EDT 2012


On Fri, Sep 14, 2012 at 06:39:46PM +0100, Catalin Marinas wrote:
> On Fri, Sep 14, 2012 at 06:31:59PM +0100, Arnd Bergmann wrote:
> > On Friday 14 September 2012, Catalin Marinas wrote:
> > > (revisiting unanswered emails :))
> > > 
> > > On Wed, Aug 15, 2012 at 01:33:55AM +0100, Olof Johansson wrote:
> > > > On Tue, Aug 14, 2012 at 06:52:14PM +0100, Catalin Marinas wrote:
> > > > > +/*
> > > > > + *  I/O port access primitives.
> > > > > + */
> > > > > +#define IO_SPACE_LIMIT             0xffff
> > > > > +
> > > > > +/*
> > > > > + * We currently don't have any platform with PCI support, so just leave this
> > > > > + * defined to 0 until needed.
> > > > > + */
> > > > > +#define PCI_IOBASE         ((void __iomem *)0)
> > > > 
> > > > You could just leave out the PCI / I/O code alltogether instead.
> > > 
> > > I would leave this in as some of the first platforms to appear will have
> > > PCIe. At some point we'll add a fixed address where the PCI_IOBASE is
> > > mapped.
> > > 
> > 
> > I guess the cleanest way would be to reserve a virtual memory region right away
> > and document it in the file where you describe the memory layout. Then you can
> > fill the value in here.
> 
> Yes, easy to do. Any access will fault until we add the PCI support.

Sounds good to me.


-Olof



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