From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Marek Szyprowski <m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Cc: linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
Bartlomiej Zolnierkiewicz
<b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Subject: Re: [PATCH 1/2] iommu: call detach also for default_domain before attaching to new one
Date: Thu, 25 Feb 2016 15:01:10 +0100 [thread overview]
Message-ID: <20160225140110.GB16675@8bytes.org> (raw)
In-Reply-To: <56C486EE.5020504-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Hi Marek,
On Wed, Feb 17, 2016 at 03:42:54PM +0100, Marek Szyprowski wrote:
> From driver perspective the default_domains don't really differ from the
> 'other' domains. They are just allocated from the IOMMU core and used by
> the IOMMU/DMA-mapping glue code. That's what I got from reading the code.
>
> There should be also a way to detach the driver even from the default domain
> to implement the arch_tear_down_dma_ops function.
The attaching/detaching in the iommu-core only manages software state.
The iommu-driver can power-down the iommu device when the default-domain
is attached and it does not expect any map/unmap calls.
All it has to make sure is that it wakes up the iommu device again when
or before these calls are made again.
Joerg
next prev parent reply other threads:[~2016-02-25 14:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-16 14:40 [PATCH 0/2] iommu: fix handling of attach/detach for default domains Marek Szyprowski
[not found] ` <1455633632-16873-1-git-send-email-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-02-16 14:40 ` [PATCH 1/2] iommu: call detach also for default_domain before attaching to new one Marek Szyprowski
[not found] ` <1455633632-16873-2-git-send-email-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-02-16 15:59 ` Joerg Roedel
[not found] ` <20160216155922.GV18805-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2016-02-17 7:35 ` Marek Szyprowski
[not found] ` <56C422AE.9000108-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-02-17 11:14 ` Joerg Roedel
[not found] ` <20160217111450.GA18805-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2016-02-17 14:42 ` Marek Szyprowski
[not found] ` <56C486EE.5020504-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-02-25 14:01 ` Joerg Roedel [this message]
2016-02-16 14:40 ` [PATCH 2/2] iommu: fix default domain handling in __iommu_detach_group() Marek Szyprowski
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