From: Matt Porter <mporter@kernel•crashing.org>
To: Rune Torgersen <runet@innovsys•com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: Lots of memory on 826x
Date: Tue, 8 Mar 2005 16:30:01 -0700 [thread overview]
Message-ID: <20050308163001.D8434@cox.net> (raw)
In-Reply-To: <DCEAAC0833DD314AB0B58112AD99B93B8592EB@ismail.innsys.innovsys.com>; from runet@innovsys.com on Tue, Mar 08, 2005 at 05:20:38PM -0600
On Tue, Mar 08, 2005 at 05:20:38PM -0600, Rune Torgersen wrote:
> > -----Original Message-----
> > From: Kumar Gala [mailto:kumar.gala@freescale•com]
> > Sent: Tuesday, March 08, 2005 17:14
> > To: Rune Torgersen
> > Cc: linuxppc-embedded@ozlabs•org; Matt Porter
> > Subject: Re: Lots of memory on 826x
> >
> > Hmm, I think there is an expectation that virt->phys is a simple
> > translation (ie, subtract KERNELBASE) for lowmem. lowmem most parts
> > tops out at 768M. So changing VMALLOC_START would break that.
>
> Yep noticed..... (tried changing it...)
Yeah, sorry, got busy and couldn't reply to say, "don't do that!". :)
> > Is there an issue with moving the IMMR virt address up higher?
> Not really. Will have to redo a whole lot of address maps for some
> external devices, but not too bad...
>
> I did change the kernel start address, and that seems to work better,
> except that things is still broken when CONFIG_HIGHMEM is set
> When that option is set, it maps the highmem to 0xFE000000, which is in
> the IO area mapped for IMMR and other memory mapped devices.
> (0xF0000000-0xFFFFFFFF)
>
> This can be changed by CONFIG_HIGHMEM_START. Any good ideas on where to
> move it to?
>
> (Maybe change IMMR/IO to 0xF8000000 and up, and set HIGHMEM_START to
> 0xF0000000?)
Ahh, but early ioremaps (before mm is inited) grow down from PKMAP_BASE,
so you will be overlapping the top of lowmem with those allocations.
It wants to be above vmalloc space. Set HIGHMEM_START to 0xF6000000,
IMMR/IO to 0xF8000000 and you then have vmalloc space between
0xF1000000-0xF5FFFFFF.
-Matt
next prev parent reply other threads:[~2005-03-08 23:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-08 23:20 Lots of memory on 826x Rune Torgersen
2005-03-08 23:30 ` Matt Porter [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-03-09 17:52 Rune Torgersen
2005-03-08 23:35 Rune Torgersen
2005-03-08 23:39 ` Matt Porter
2005-03-08 21:16 Rune Torgersen
2005-03-08 23:13 ` Kumar Gala
2005-03-08 18:37 Rune Torgersen
2005-03-08 18:54 ` Mark Chambers
2005-03-08 20:32 ` Matt Porter
2005-03-08 17:33 Rune Torgersen
2005-03-08 18:06 ` Kumar Gala
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