Re: [PATCH 0/5][RFC] Physical PCI slot objects

Bjorn Helgaas
2007-11-13T22:01:07Z

On Tuesday 13 November 2007 02:30:49 pm Greg KH wrote:
> On Tue, Nov 13, 2007 at 01:36:45PM -0700, Alex Chiang wrote:
> > * Greg KH <greg@kroah.com>:
> > > IBM sells a program that does this for server rooms. It's
> > > probably part of some Tivoli package somewhere, sorry I don't
> > > remember the name. I did see it working many years ago and it
> > > required no kernel changes at all to work properly.

Do you know how this Tivoli package works or where it gets the
information?

> > Like I said in an earlier email, HP ia64 systems will require a
> > kernel change to get this information. Whether it comes via a
> > generic ACPI access layer like dev_acpi, or something like this
> > patch series, the kernel will still get touched.
>
> And like I said, I'm pretty sure you don't need to touch the kernel
> today as there are people doing this just fine from userspace without
> any kernel changes needed :)

I think you are assuming userspace can just dump the raw ACPI tables
and extract this information from them. But I don't think that's
possible because _SUN is a method that can contain arbitrary AML.
That AML has to be *executed*, and you can't do that safely in
userspace.

Bjorn