From: Joerg Roedel <joro@8bytes.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: iommu@lists.linux-foundation.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Joerg Roedel <jroedel@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] iommu/of: Use device_iommu_mapped()
Date: Thu, 6 Dec 2018 16:35:12 +0100 [thread overview]
Message-ID: <20181206153512.GG16835@8bytes.org> (raw)
In-Reply-To: <44c82503-bc36-e8de-6932-7c4fd2b597f8@arm.com>
Hi Robin,
On Wed, Dec 05, 2018 at 05:17:54PM +0000, Robin Murphy wrote:
> FWIW, this check (and its ACPI equivalent in patch #3) is specifically
> asking "has .add_device() already been called?", rather than the more
> general "is this device managed by an IOMMU?" (to which the exact answer at
> this point is "yes, provided we return successfully from here").
>
> I have no objection to the change as-is - especially if that usage is within
> the intended scope of this API - I just wanted to call it out in case you're
> also planning to introduce something else which would be even more
> appropriate for that.
Yes, the purpose of the device_iommu_mapped() functions is to check
whether the device has been initialized by the IOMMU driver that handles
it, if any.
So it answers the question: Can I use the device in an IOMMU-API call?
And it is more readable than the dev->iommu_group checks everywhere :)
Regards,
Joerg
next prev parent reply other threads:[~2018-12-06 15:35 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-04 17:24 [PATCH 0/5] Introduce device_iommu_maped() function Joerg Roedel
2018-12-04 17:25 ` [PATCH 1/5] driver core: Introduce device_iommu_mapped() function Joerg Roedel
2018-12-06 12:55 ` Greg Kroah-Hartman
2018-12-06 15:39 ` Joerg Roedel
2018-12-04 17:25 ` [PATCH 2/5] iommu/of: Use device_iommu_mapped() Joerg Roedel
2018-12-05 17:17 ` Robin Murphy
2018-12-06 15:35 ` Joerg Roedel [this message]
2018-12-06 17:42 ` Robin Murphy
2018-12-07 9:31 ` Joerg Roedel
2018-12-04 17:25 ` [PATCH 3/5] ACPI/IORT: " Joerg Roedel
2018-12-04 17:25 ` [PATCH 4/5] powerpc/iommu: " Joerg Roedel
2018-12-04 17:25 ` [PATCH 5/5] xhci: " Joerg Roedel
2018-12-05 17:17 ` [PATCH 0/5] Introduce device_iommu_maped() function Robin Murphy
2018-12-06 15:36 ` Joerg Roedel
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