From: Keir Fraser <keir@xensource.com>
To: Jan Beulich <jbeulich@novell.com>, Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: xen-devel@lists.xensource.com
Subject: Re: early_cpu_init() and identify_cpu()
Date: Tue, 17 Jul 2007 11:23:27 +0100 [thread overview]
Message-ID: <C2C2572F.12905%keir@xensource.com> (raw)
In-Reply-To: <C2C25554.128FF%keir@xensource.com>
On 17/7/07 11:15, "Keir Fraser" <keir@xensource.com> wrote:
> If we just mapped the 4kB-rounded region specified by lfb_base to
> lfb_base+lfb_size (as determined via the VBE Get Mode Info call) as WC,
> would that be safe?
Actually this is probably okay because any software that does want to access
command queues (e.g., X server) will have its own mapping that will not
specify PAT.WC. In contrast MTRR type specification is used by all mappings
of that physical address range. So long as aliasing of WC and UC was not a
problem, this would work fine. But I think it's WC aliasing with WB/WT that
is a problem.
-- Keir
next prev parent reply other threads:[~2007-07-17 10:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-13 16:16 early_cpu_init() and identify_cpu() Jan Beulich
2007-07-13 16:26 ` Keir Fraser
2007-07-16 6:14 ` Jan Beulich
2007-07-16 6:25 ` Keir Fraser
2007-07-16 6:41 ` Jan Beulich
2007-07-16 6:57 ` Keir Fraser
2007-07-16 7:01 ` Keir Fraser
2007-07-16 7:31 ` Jan Beulich
2007-07-16 7:30 ` Jan Beulich
2007-07-16 9:23 ` Alan Cox
2007-07-17 7:55 ` Keir Fraser
2007-07-17 10:00 ` Jan Beulich
2007-07-17 10:15 ` Keir Fraser
2007-07-17 10:23 ` Keir Fraser [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-07-16 8:18 Jan Beulich
2007-07-17 7:50 ` Keir Fraser
2007-07-17 9:58 ` Jan Beulich
2007-07-17 10:05 ` Keir Fraser
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