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From:   Julius Werner <jwerner@chromium.org>
Date:   Thu, 9 Aug 2018 14:07:31 -0700
Message-ID: <CAODwPW8eg2WOh9-Raeb8Q65E-5D7RDheDU8e+H68FHGa0MS37A@mail.gmail.com>
Subject: Re: [PATCH v3 7/7] firmware: coreboot: Request table region for
 exclusive access
To:     swboyd@chromium.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Wei-Ning Huang <wnhuang@chromium.org>,
        Julius Werner <jwerner@chromium.org>,
        Brian Norris <briannorris@chromium.org>, samuel@sholland.org
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On Thu, Aug 9, 2018 at 10:17 AM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Call request_mem_region() on the entire coreboot table to make sure
> other devices don't attempt to map the coreboot table in their drivers.
> If drivers need that support, it would be better to provide bus APIs
> they can use to do that through the mapping created in this file.
>

Does this prevent userspace from mapping this region via /dev/mem? If
so, let's please not do it to not break compatibility with existing
tools. (I guess an alternative would be to rewrite 'cbmem' to use
/sys/bus/coreboot/devices if available to get its coreboot table
information. But we'd still need to maintain the old path for
backwards compatibility anyway, so that would really just make it more
complicated.)