Re: [PATCH] altix: Add volatile qualifiers in places where it seems necessary

Christoph Hellwig
2005-09-02T16:12:33Z

On Fri, Sep 02, 2005 at 11:08:58AM -0500, Mark Maule wrote:
> On Fri, Sep 02, 2005 at 04:49:53PM +0100, Christoph Hellwig wrote:
> > On Fri, Sep 02, 2005 at 10:41:52AM -0500, Mark Maule wrote:
> > > On Fri, Sep 02, 2005 at 04:38:09PM +0100, Christoph Hellwig wrote:
> > > > On Fri, Sep 02, 2005 at 10:36:12AM -0500, Mark Maule wrote:
> > > > > Add missing volatile qualifier to hardware MMR pointers in various SN files.
> > > > > Cosmetic code rearranging in pcibr_reg.c to avoid line-wraps.
> > > >
> > > > Volatile usage is wrong most of the time, and your use is certainly.
> > > > It seems you're accessing mmio-space or something similar and should
> > > > use proper acessors for it.
> > > >
> > >
> > > Okay. In these cases, I am indeed accessing mapped reisters. I don't know
> > > what you mean by "proper acessors", so a reference would be appreciated.
> >
> > ioread<N> / iowrite<N>
>
> Would readq_relaxed()/writeq() be adequate?

Yes, I think so. In fact you might even want to __sn_read*/__sn_write*
directly as this code runs only on SN2, and you can avoid the unessecary
indirection for generic kernels.