On Sat, 2005-12-17 at 14:19 -0800, Robert Walsh wrote:
> > > +{
> > > + void *ssv, *dsv;
> > > + uint32_t csv;
> > > + __asm__ __volatile__("cld\n\trep\n\tmovsb":"=&c"(csv), "=&D"(dsv),
> > > + "=&S"(ssv)
> > > + :"0"(cnt), "1"(dest), "2"(src)
> > > + :"memory");
> > > +}
> >
> > No way we're gonna put assembler code into such a driver.
>
> Why not? The chip (and therefore the driver) only works with Opterons.
> It's tied to the HT bus, but PCI or anything like that.
and opterons can already run 2 architectures. And the HT bus is a
generic bus.. with public specs. Others than just AMD use it as well.
also.. what is wrong with memcpy and co ?
> > > +static __inline__ uint32_t ipath_kget_kreg32(const ipath_type stype,
> > > + ipath_kreg regno)
> > > +{
> > > + volatile uint32_t *kreg32;
> > > +
> > > + if (!devdata[stype].ipath_kregbase)
> > > + return ~0;
> > > +
> > > + kreg32 = (volatile uint32_t *)&devdata[stype].ipath_kregbase[regno];
> >
> > volatile use is probably always wrong. but this whole functions looks like
> > a very odd wrapper anyway?
>
> The volatile is there so the compiler doesn't optimize away the read.
> This is important, because reads of our hardware have side-effects and
> cannot be optimized out.
then you need to use readl() and family most like; they already take
care of this anyway.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
