From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 10/28] i386: map enough initial memory to create lowmem
 mappings
Date: Mon, 23 Apr 2007 13:41:38 -0700
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To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: lkml <linux-kernel@vger.kernel.org>, Chris Wright <chrisw@sous-sol.org>, virtualization@lists.osdl.org, Chuck Ebbert <cebbert@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Linus Torvalds <torvalds@linux-foundation.org>
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Eric W. Biederman wrote:
> Jeremy Fitzhardinge <jeremy@goop.org> writes:
> 
>> H. Peter Anvin wrote:
>>> It would be *trivial* to make a certain number of page table slots
>>> available at the end of the head.S-generated map. 
>> Or you could use a fixmap.
> 
> That certain number of page table slots should be the fixmap slots.
> If you do that bt_ioremap works, we remove a boatload of special cases
> and the code becomes simpler.

It's probably worth noting that several of the non-PC ports already do 
exactly this, although in a hacky way.  Grep for pg0 and you'll find it.

	-hpa