From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shaohua Li <shaohua.li@intel.com>
Subject: Re: [PATCH] ACPI: use ioremap_cache()
Date: Tue, 28 Dec 2010 13:02:20 +0800
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To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>, Jack Steiner <steiner@sgi.com>, Henrique de Moraes Holschuh <hmh@hmh.eng.br>, "tony.luck@gmail.com" <tony.luck@gmail.com>, "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "gbeshers@sgi.com" <gbeshers@sgi.com>

On Tue, 2010-12-28 at 11:35 +0800, H. Peter Anvin wrote:
> On 12/27/2010 07:21 PM, Shaohua Li wrote:
> > RCRB is a memory mapped io. In ICH, it's chipset configuration
> > registers. this range can't be cached.
> > I thought we should add a check like
> > if page is E820_RAM or E820_ACPI then
> > 	cached_map
> > else
> > 	uncached_map
> > we have page_is_ram() API which just checks E820_RAM, I thought we can
> > add a new API to check E820_ACPI.
> 
> For x86, that is handled by the MTRRs; 
does it cause any problem if the pat and mtrr doesn't match?