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From: Kumar Gala <galak@kernel.crashing.org>
Subject: Re: [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to
	generic iopa
Date: Thu, 8 Feb 2007 01:16:19 -0600
To: "Li Yang-r58472" <LeoLi@freescale.com>
Cc: netdev@vger.kernel.org, Tabi Timur-B04825 <timur@freescale.com>,
	linuxppc-dev@ozlabs.org
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On Feb 8, 2007, at 1:06 AM, Li Yang-r58472 wrote:

>>> MURAM is a mmio region so it don't share the characteristic of main
>>> memory that phy_addr = virt_addr - PAGE_OFFSET.  While they can
>>> both be
>>> mapped through page table using iopa().
>>
>> Right, so when do you know if you'll be using MURAM or normal
>> memory?  Why not just keep around a token that is the physical
>> address at the point you make the decision of MURAM vs normal memory.
>
> Yes, that can be a way.  But as the virt to phy mapping is only used
> once, it's nothing bad to do it this way.

The problem as I stated before with using iopa() is that its not  
supported across platforms.

- k