From: Sethi Varun-B16395 <B16395@freescale.com>
To: Yoder Stuart-B08248 <B08248@freescale.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Wood Scott-B07421 <B07421@freescale.com>,
Alex Williamson <alex.williamson@redhat.com>,
Joerg Roedel <joro@8bytes.org>,
"linux-kernel@vger.kernel.org list"
<linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Paul Mackerras <paulus@samba.org>,
"linuxppc-dev@lists.ozlabs.org list"
<linuxppc-dev@lists.ozlabs.org>,
David Gibson <david@gibson.dropbear.id.au>
Subject: RE: [PATCH 1/6 v8] iommu/fsl: Store iommu domain information pointer in archdata.
Date: Mon, 4 Mar 2013 06:35:55 +0000 [thread overview]
Message-ID: <C5ECD7A89D1DC44195F34B25E172658D3D06A1@039-SN2MPN1-013.039d.mgd.msft.net> (raw)
In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E1503565876@039-SN1MPN1-003.039d.mgd.msft.net>
> -----Original Message-----
> From: Yoder Stuart-B08248
> Sent: Friday, March 01, 2013 9:52 PM
> To: Alexey Kardashevskiy; Sethi Varun-B16395
> Cc: Kumar Gala; Benjamin Herrenschmidt; iommu@lists.linux-foundation.org;
> linuxppc-dev@lists.ozlabs.org list; linux-kernel@vger.kernel.org list;
> Wood Scott-B07421; Joerg Roedel; Paul Mackerras; David Gibson; Alex
> Williamson
> Subject: RE: [PATCH 1/6 v8] iommu/fsl: Store iommu domain information
> pointer in archdata.
>=20
>=20
>=20
> > -----Original Message-----
> > From: Alexey Kardashevskiy [mailto:aik@ozlabs.ru]
> > Sent: Friday, March 01, 2013 4:07 AM
> > To: Sethi Varun-B16395
> > Cc: Kumar Gala; Benjamin Herrenschmidt;
> > iommu@lists.linux-foundation.org; linuxppc-dev@lists.ozlabs.org list;
> > linux-kernel@vger.kernel.org list; Wood Scott-B07421; Yoder
> > Stuart-B08248; Joerg Roedel; Paul Mackerras; David Gibson; Alex
> > Williamson
> > Subject: Re: [PATCH 1/6 v8] iommu/fsl: Store iommu domain information
> pointer in archdata.
> >
> > btw the device struct already has a pointer to its iommu_group, and
> > the iommu_group struct itself has a pointer void *iommu_data which you
> > could use for anything you want (iommu_group_get_iommudata(),
> > iommu_group_set_iommudata()).
> >
> > By design you are expected to add iommu groups to a domain but not
> > devices so I am not so sure that you really need a pointer to domain
> > in the device struct.
>=20
> Well, at the lowest level the IOMMU API does attach devices to domains--
> i.e.
> API attach_dev(). So, it seems to conceptually make sense to have a ptr
> from the device to the associated domain. When you implement
> attach_dev() you need to be able to see whether the device is already
> attached to
> a domain. Adding a couple of levels of indirection...from device to
> group to domain...doesn't seems to make things simpler or better IMHO.
>=20
> x86 keeps a pointer to the domain in device archdata and since there is a
> direct correlation between a device and domain I'd rather see it where
> this patch has it.
>=20
As Stuart stated this allows us to maintain the device <-> domain relations=
hip at the lowest level.
-Varun
next prev parent reply other threads:[~2013-03-04 6:36 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 12:52 [PATCH 0/6 v8] iommu/fsl: Freescale PAMU driver and IOMMU API implementation Varun Sethi
2013-02-18 12:52 ` [PATCH 1/6 v8] iommu/fsl: Store iommu domain information pointer in archdata Varun Sethi
2013-02-27 11:30 ` Joerg Roedel
2013-02-27 12:04 ` Sethi Varun-B16395
2013-02-28 15:51 ` Kumar Gala
2013-03-01 1:24 ` Alexey Kardashevskiy
2013-03-01 8:55 ` Sethi Varun-B16395
2013-03-01 10:07 ` Alexey Kardashevskiy
2013-03-01 16:21 ` Yoder Stuart-B08248
2013-03-04 6:35 ` Sethi Varun-B16395 [this message]
2013-02-18 12:52 ` [PATCH 2/6] powerpc/fsl_pci: Store the platform device information corresponding to the pci controller Varun Sethi
2013-02-26 0:09 ` Stuart Yoder
2013-02-26 6:16 ` Sethi Varun-B16395
2013-02-27 10:45 ` Joerg Roedel
2013-02-27 10:56 ` Sethi Varun-B16395
2013-02-28 15:45 ` Kumar Gala
2013-03-07 9:14 ` Sethi Varun-B16395
2013-03-07 10:37 ` Joerg Roedel
2013-02-18 12:52 ` [PATCH 3/6] powerpc/fsl_pci: Added defines for the FSL PCI controller BRR1 register Varun Sethi
2013-02-27 11:33 ` Joerg Roedel
2013-02-28 15:46 ` Kumar Gala
2013-02-18 12:52 ` [PATCH 4/6] iommu/fsl: Add window permission flags for iommu_domain_window_enable API Varun Sethi
2013-02-18 12:52 ` [PATCH 5/6 v8] iommu/fsl: Add addtional attributes specific to the PAMU driver Varun Sethi
2013-02-27 11:38 ` Joerg Roedel
2013-02-18 12:52 ` [PATCH 6/6 v8] iommu/fsl: Freescale PAMU driver and IOMMU API implementation Varun Sethi
2013-02-19 10:04 ` Diana Craciun
2013-02-19 10:27 ` Sethi Varun-B16395
2013-02-19 15:59 ` Diana Craciun
2013-02-20 9:41 ` Sethi Varun-B16395
2013-02-26 22:33 ` Stuart Yoder
2013-02-27 11:56 ` Sethi Varun-B16395
2013-02-28 0:03 ` Stuart Yoder
2013-03-01 23:27 ` Stuart Yoder
2013-03-04 11:31 ` Sethi Varun-B16395
2013-03-04 16:55 ` Yoder Stuart-B08248
2013-02-25 10:15 ` [PATCH 0/6 " Sethi Varun-B16395
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