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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Mon, 4 Mar 2019 22:23:11 +0100
Message-ID: <CAK8P3a1NXXNBUzb7tHtF6ohCcR+_rFhxXSd3ziSmnkhg7bdrpA@mail.gmail.com>
Subject: Re: [PATCH] xen: avoid link error on ARM
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc:     Juergen Gross <jgross@suse.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 Mon, Mar 4, 2019 at 10:19 PM Boris Ostrovsky
<boris.ostrovsky@oracle.com> wrote:
>
> On 3/4/19 3:47 PM, Arnd Bergmann wrote:
> > Building the privcmd code as a loadable module on ARM, we get
> > a link error due to the private cache management functions:
> >
> > ERROR: "__sync_icache_dcache" [drivers/xen/xen-privcmd.ko] undefined!
>
> Can __sync_icache_dcache be exported in arm32, just like it is in arm64?

Russell wants all cache management operations to stay private to the
kernel, as they tend to get abused by other drivers:

https://lore.kernel.org/linux-arm-kernel/20181218100908.GL26090@n2100.armlinux.org.uk/

      Arnd