Re: [PATCH 1/2] arm: msm: Add System MMU support.

From: Roedel, Joerg
Date: Tue Aug 03 2010 - 05:23:42 EST

On Mon, Aug 02, 2010 at 04:29:38PM -0400, Zach Pfeffer wrote:
> On Mon, Aug 02, 2010 at 09:58:02AM +0200, Roedel, Joerg wrote:

> > In the means of the IOMMU-API the domain is the abstraction of an
> > address space (in other words a page table). The IOMMU(s) which this domain
> > is later assigned to are determined by the iommu_attach_device calls.
> > I think the right way to go here is to create the concept of a
> > device-context in the IOMMU-API and add functions like
> >
> > iommu_attach_context(struct iommu_domain *domain,
> > struct iommu_context *ctxt);
> > iommu_detach_context(struct iommu_context *ctxt);
> >
> > This would work if you can determine in your iommu-driver which iommu
> > you need to program for which device. What do you think?
> >
> Joerg, I'd like to make sure I understand this. A domain is an address
> space separate from the actual page-tables that may be part of an
> iommu_context, correct? After I iommu_attach_context the ctxt will
> reflect the address space of the domain, correct?

A domain is defined by a single page-table which can be modified using
the iommu_map/iommu_unmap function calls. I am not completly sure what
you mean by an iommu_context. Can you describe what it means in your


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