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From: Grant Likely <grant.likely@secretlab.ca>
Date: Wed, 7 Jul 2010 23:38:12 -0600
Message-ID: <AANLkTilNssNdEW3wBKfoUMbSQMFLywfFgGMb0F9XwKeG@mail.gmail.com>
Subject: Re: [PATCH] arch/powerpc/lib/copy_32.S: Use alternate memcpy for
	MPC512x and MPC52xx
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Cc: Steve Deiters <SteveDeiters@basler.com>, linuxppc-dev@lists.ozlabs.org
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On Wed, Jul 7, 2010 at 11:10 PM, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
> On Tue, 2010-06-29 at 11:04 -0500, Steve Deiters wrote:
>> These processors will corrupt data if accessing the local bus with
>> unaligned
>> addresses. This version fixes the typical case of copying from Flash on
>> the
>> local bus by keeping the source address always aligned.
>
> Shouldn't this be solved by using memcpy_to/fromio ?

Maybe.  plain memcpy() access to anything localbus-attached on the
mpc5xxx is the wrong thing to do.  memcpy_to/fromio might do the right
thing; but the caller must understand the limitations of the localplus
bus.  The byte-wise alignment that memcpy_to/fromio() does may not
work (depending on configuration).

Steve, what code is doing a memcpy from flash?

g.