[Xorg] The big multiconsole nasty
jbarnes at engr.sgi.com
Tue Jul 13 12:25:55 PDT 2004
On Tuesday, July 13, 2004 3:09 pm, Egbert Eich wrote:
> Jesse Barnes writes:
> > In the arch specific in/out routines you mean? I see lots of lines like
> > inb(0x3c8) in various drivers and other code...
> Can you point me to them, please?
There are too many to list. Just do a 'grep -r inb' in hw/xorg. Many of the
inb calls refer to a base, but in some cases (maybe all cases) the IOBase is
assumed to be global and unique, rather than per-device or per-bus.
> > in/out is pretty slow already, and is only used at startup time, afaict.
> > Most code just does memory reads/writes to register space doesn't it?
> This depends very much on the driver.
Right, that's what I was getting at. If there are drivers that use in/out as
their main means of talking to their device, then we'll want to be careful to
keep them fast. Otherwise, performance of those routines isn't very
> Are you sure? I mean I didn't implement it, but I always had the impression
> that the offset values in all the IO code was introduced for that purpose.
Depends on the arch. ppc has a global IObase, ia64 doesn't use one at all,
but I think sparc might be able to deal with multiple base (but like I said
above, I don't think the rest of the code is ready).
> I'll take a look later.
Ok, thanks for looking.
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