[PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa

[Li Yang-r58472]

> -----Original Message-----
> From: Kumar Gala [mailto:galak at kernel.crashing.org]
> Sent: Thursday, February 08, 2007 3:16 PM
> To: Li Yang-r58472
> Cc: Tabi Timur-B04825; netdev at vger.kernel.org; linuxppc-dev at ozlabs.org
> Subject: Re: [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys
to generic
> iopa
> 
> 
> 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.

Yes, it is only for PPC32.  But we don't have another API to do it.  How
about make it more generic to add PPC64 version?

- Leo