From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from exg.allot.com (mail.allot.com [199.203.223.202]) by ozlabs.org (Postfix) with ESMTP id 454F42BDEB for ; Thu, 11 Nov 2004 07:24:24 +1100 (EST) Message-ID: <41925FDC.1060308@allot.com> Date: Wed, 10 Nov 2004 20:37:16 +0200 From: Felix Radensky MIME-Version: 1.0 To: Matt Porter References: <4190FDED.3080605@allot.com> <20041109111707.A14471@home.com> In-Reply-To: <20041109111707.A14471@home.com> Content-Type: multipart/alternative; boundary="------------090101040903040904090800" Cc: linuxppc-embedded@ozlabs.org Subject: Re: 405GPr ioremap problem List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a multi-part message in MIME format. --------------090101040903040904090800 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi, Matt Thanks a lot for replying, your help is very much appreciated. I've followed your suggestion and now ioremap works as expected. I've removed ivocation of m4xx_map_io() replacing it by normal ioremaps for serial ports, RTC and ethernet adapter. It would be great to see this stuff cleaned up in 2.6. Felix. Matt Porter wrote: >On Tue, Nov 09, 2004 at 07:27:09PM +0200, Felix Radensky wrote: > > >>Hi, folks >> >>I have a 405GPr based board with 512M of RAM. >>My kernel is 2.4.17 from Monta Vista Linux 2.1. >>I'm trying to reserve 64M on boot using mem=448M >>and map it later by >> >>ioremap(__pa(high_memory), 64*(1<<20)); >> >>This worked fine when system had 256M of RAM, >>but now ioremap fails. If I understand the kernel >>code correctly, by adding more RAM I've reduced >>the vmalloc/ioremap space. I can also see that this >>space is reduced dramatically on boot by mappings >>done in arch/ppc/kernel/ppc4xx_setup.c:m4xx_map_io() >> >>Is there any way to fix problem ? Is it necessary to have >>a 1:1 virtual to physical mappings as its done in m4xx_map_io() >>or maybe higher virtual addresses can be used, thus >>allowing to save some precious ioremap space. >> >> > >This is exactly why the PPC44x ports don't use io_block_map()... >it can interfere with dynamic mappings. It is not necessary to >have 1:1 virtual to physical mappings nor is it necessary to >have m4xx_map_io() at all. One can use ioremap() to map any >space and let the kernel place things intelligently. In order >to use serial console you'll have to use early_serial_setup() >after you've ioremapped the UART...once you've removed the >io_block_map() call. Look at other ports to see how this is >done. > >Someday I might get down my list to cleaning up 40x stuff in 2.6. > >-Matt > > > --------------090101040903040904090800 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, Matt

Thanks a lot for replying, your help is very much
appreciated. I've followed your suggestion and now
ioremap works as expected. I've removed ivocation
of m4xx_map_io() replacing it by normal ioremaps
for serial ports, RTC and ethernet adapter.

It would be great to see this stuff cleaned up in 2.6.

Felix.


Matt Porter wrote: 
On Tue, Nov 09, 2004 at 07:27:09PM +0200, Felix Radensky wrote:
  
Hi, folks

I have a 405GPr based board with 512M of RAM.
My kernel is 2.4.17 from Monta Vista Linux 2.1.
I'm  trying to reserve 64M on boot using mem=448M
and map it later by

ioremap(__pa(high_memory), 64*(1<<20));

This worked fine when system had 256M of RAM,
but now ioremap fails. If I understand the kernel
code correctly, by adding more RAM I've reduced
the vmalloc/ioremap space. I can also see that this
space is reduced dramatically on boot by mappings
done in arch/ppc/kernel/ppc4xx_setup.c:m4xx_map_io()

Is there any way to fix problem ? Is it necessary to have
a 1:1 virtual to physical mappings as its done in m4xx_map_io()
or maybe higher virtual addresses can be used, thus
allowing to save some precious ioremap space.
    

This is exactly why the PPC44x ports don't use io_block_map()...
it can interfere with dynamic mappings.  It is not necessary to
have 1:1 virtual to physical mappings nor is it necessary to
have m4xx_map_io() at all. One can use ioremap() to map any
space and let the kernel place things intelligently. In order
to use serial console you'll have to use early_serial_setup()
after you've ioremapped the UART...once you've removed the
io_block_map() call. Look at other ports to see how this is
done.

Someday I might get down my list to cleaning up 40x stuff in 2.6.

-Matt
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