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Subject: Re: [PATCH] xen: avoid link error on ARM
To:     Arnd Bergmann <arnd@arndb.de>
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>
References: <20190304204826.2414365-1-arnd@arndb.de>
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 <CAK8P3a3vbjOzKAD6zce09Gc438tW=nYuMAJCE0MrODhBjO71xg@mail.gmail.com>
From:   Juergen Gross <jgross@suse.com>
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Message-ID: <a1ff4ef4-f20f-ff0c-f779-0c8a3c1acd39@suse.com>
Date:   Tue, 5 Mar 2019 10:05:33 +0100
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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.

I'll send a followup patch to move the mentioned variables into the new
source.


Juergen