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Date:   Tue, 13 Aug 2019 22:55:25 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, npiggin@gmail.com,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 05/10] powerpc/mm: Do early ioremaps from top to
 bottom on PPC64 too.
Message-ID: <20190814055525.GA12744@infradead.org>
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On Tue, Aug 13, 2019 at 08:11:38PM +0000, Christophe Leroy wrote:
> Until vmalloc system is up and running, ioremap basically
> allocates addresses at the border of the IOREMAP area.

Note that while a few other architectures have a magic hack like powerpc
to make ioremap work before vmalloc, the normal practice would be
to explicitly use early_ioremap.  I guess your change is fine for now,
but it might make sense convert powerpc to the explicit early_ioremap
scheme as well.