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Subject: Re: [PATCH] drivers/block/xsysace - replace
 in(out)_8/in(out)_be16/in(out)_le16 with generic iowrite(read)8/16(be)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Michal Simek <monstr@monstr.eu>
Cc: Arnd Bergmann <arnd@arndb.de>, Geert Uytterhoeven <geert@linux-m68k.org>,
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Date: Tue, 12 Feb 2013 11:25:26 +1100
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On Mon, 2013-02-11 at 16:57 +0100, Michal Simek wrote:
> But it reminds me that maybe the easiest solution is not to use endian
> accessors just use two simple macros which should work on all systems.
> 
> #define <name>_readreg(offset)          ({__raw_readl(offset); rmb(); })
> #define <name>_writereg(offset, val)    ({wmb(); __raw_writel(val, offset); })
> 
> which is probably the faster solution which add minimum additional code
> to driver and can also remove endian detection code.

Except that rmb & wmb might not be the right barriers for IOs ...

Cheers,
Ben.