[PATCH 2/2] I/O port access routines

Mark Kettenis mark.kettenis at xs4all.nl
Thu Nov 19 11:24:20 PST 2009

> From: Adam Jackson <ajax at redhat.com>
> Date: Thu, 19 Nov 2009 13:58:52 -0500
> On Thu, 2009-11-19 at 18:25 +0100, Luc Verhaegen wrote:
> > The baby was thrown out with the bathwater with libpciaccess and vga 
> > arbitration, and now suddenly the plan seems to be to put these new 
> > enable/disable hooks all over the driver, together with slightly more 
> > involved IN/OUT calls.
> The enable/disable thing, no.  That wrapping is in the server.  You
> don't have to do it from your driver.
> You seem to be putting words in my mouth with the in/out stuff though.
> I haven't actually said anything (yet) about whether the drivers may
> continue to use the old in/out calls.  All I've done here is add API to
> the hardware access library to let me get at the third of the three
> address spaces the hardware exposes.

While I'm sympathetic too many of the things Luc is saying, Adam is
right here.  The new interfaces will allow you to access PCI I/O BARs
(and only that particular I/O BAR) and do so in a way that also works
right for machines that have multiple PCI domains.  That is something
the old code simply didn't support.

This patch is (almost) exactly the functionality I need to make the
i128 driver work on OpenBSD/sparc64.

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