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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 5 Mar 2019 10:19:42 +0100
Message-ID: <CAK8P3a0qaeyYfKdPXdu8NXmXKVuYvr2NWXkYjnpb+UZzuRD5=w@mail.gmail.com>
Subject: Re: [PATCH] xen: avoid link error on ARM
To:     Juergen Gross <jgross@suse.com>
Cc:     Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>,
        Matthew Wilcox <willy@infradead.org>,
        Paul Durrant <paul.durrant@citrix.com>,
        Souptick Joarder <jrdr.linux@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        xen-devel <xen-devel@lists.xenproject.org>
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On Tue, Mar 5, 2019 at 10:05 AM Juergen Gross <jgross@suse.com> wrote:
>
> On 05/03/2019 09:34, Arnd Bergmann wrote:
> > On Tue, Mar 5, 2019 at 7:39 AM Juergen Gross <jgross@suse.com> wrote:
> >
> >>
> >> Can we avoid that ifdef in the Makefile?
> >>
> >> I'd rather have an architecture independant builtin driver added which
> >> is always included for CONFIG_XEN. This would allow to move redundant
> >> stuff from arch/*/xen/ into it (e.g. xen_vcpu_id).
> >>
> >> So: rename mm.c to xen-builtin.c, use:
> >>
> >> obj-$(CONFIG_XEN) += xen-builtin.o
> >
> > Sure, I'm happy to change the naming and the Makefile logic. The way you
> > suggested sounds fine to me, but it will make the xen code slightly bigger
> > even if that code is not used. We could also have a silent Kconfig symbol
> > that turns this on and still avoid the ifdef:
> >
> > obj-$(CONFIG_XEN_BUILTIN) += xen-builtin.o
>
> That was my first thought.
>
> But looking through arch/[arm|x86]/xen/enlighten.c I found several
> global variables defined the same way. I'd like to merge those, too.
>
> So my preference is a common source for all this stuff.

Ok, makes sense. I've prepared that patch now and will send it
after some more build testing.

        Arnd