Re: [PATCH 5/5] iommu: Add DOMAIN_ATTR_WINDOWS domain attribute

From: Joerg Roedel
Date: Tue Feb 05 2013 - 08:05:41 EST


On Tue, Feb 05, 2013 at 10:52:03AM +0000, Sethi Varun-B16395 wrote:
> DOMAIN_ATTR_PAMU_ENABLE is required to enable a particular DMA window.
> My point is about the domain geometry, which is incomplete in case of
> PAMU without the number of subwindows. Geometry parameters are used
> for initializing the PAMU window settings. Individual subwindows can
> only be enabled, once the PAMU window has been initialized using the
> geometry settings.

I understand that. What you do is:

/* Set geometry */
set_attr(domain, DOMAIN_ATTR_GEOMETRY);

/* Set number of PAMU subwindows */
set_attr(domain, DOMAIN_ATTR_WINDOWS);

/* Commit changes to hardware and enable the window */
set_attr(domain, DOMAIN_ATTR_PAMU_ENABLE);

And I don't see any problem with that. The domain_attr interface was
introduced to cope with device specifics, we don't change global
interface data structures for that.


Joerg


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