Re: Opinion on ordering of writel vs. stores to RAM [LWN.net]

From:		Alan Cox <alan-AT-lxorguk.ukuu.org.uk>
To:		Benjamin Herrenschmidt <benh-AT-kernel.crashing.org>
Subject:		Re: Opinion on ordering of writel vs. stores to RAM
Date:		Sat, 09 Sep 2006 16:09:51 +0100
Cc:		Linus Torvalds <torvalds-AT-osdl.org>, Paul Mackerras <paulus-AT-samba.org>, linux-kernel-AT-vger.kernel.org, akpm-AT-osdl.org, segher-AT-kernel.crashing.org, davem-AT-davemloft.net
Archive-link:		Article, Thread

Ar Sad, 2006-09-09 am 17:23 +1000, ysgrifennodd Benjamin Herrenschmidt:
> The problem is that very few people have any clear idea of what mmiowb
> is :) In fact, what you described is not the definition of mmiowb
> according to Jesse 

Some of us talked a little about this at Linux Kongress and one
suggestion so people did understand it was

	spin_lock_io();
	spin_unlock_io();

so that it can be expressed not as a weird barrier op but as part of the
locking.

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