From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 6/7] iommu/arm-smmu: Finish off SMMUv3 default domain support
Date: Tue, 14 Jun 2016 16:59:48 +0100 [thread overview]
Message-ID: <20160614155948.GD16531@arm.com> (raw)
In-Reply-To: <aabcdd814b93b2b6a902b189f6911f929a29b64f.1464966939.git.robin.murphy@arm.com>
On Fri, Jun 03, 2016 at 06:15:41PM +0100, Robin Murphy wrote:
> The driver's current reliance on attaching/detaching an entire group
> for the first device it sees is at odds with the IOMMU core's initial
> construction of a group by adding each device and attaching it to the
> default domain in turn. As it turns out, we can happily do away with the
> whole palaver by simply letting each device be in charge of its own
> stream ID/stream table entry, and reducing the problem of tracking
> duplicate IDs and domains down to "Is the STE already associated with
> the appropriate context?", which is easily done by just looking at the
> stream table itself.
Hmm, it would be nice if Joerg could confirm this before we remove the
driver code.
Joerg: can an IOMMU driver rely on not receiving contradictory ->attach
callbacks for devices in the same group? Robin is proposing that we
remove the group tracking code from the ARM SMMU driver which is a nice
cleanup but leaves us open to silent misconfiguration if we are asked to
violate the group constraints.
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 7631639cc209..28dcc5ca237e 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -607,15 +607,6 @@ struct arm_smmu_device {
> struct arm_smmu_strtab_cfg strtab_cfg;
> };
>
> -/* SMMU private data for an IOMMU group */
> -struct arm_smmu_group {
> - struct arm_smmu_device *smmu;
> - struct arm_smmu_domain *domain;
> - int num_sids;
> - u32 *sids;
> - struct arm_smmu_strtab_ent ste;
> -};
I'm not keen on losing this structure. How about we instead change the
sids array to be a linked list of {struct device, sid[]} and then change
arm_smmu_install_ste_for_group to take a device pointer as well?
Will
next prev parent reply other threads:[~2016-06-14 15:59 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-03 17:15 [PATCH v2 0/7] Generic DT bindings for PCI IOMMUs and ARM SMMUv3 Robin Murphy
2016-06-03 17:15 ` [PATCH v2 1/7] iommu/of: Respect disabled IOMMUs Robin Murphy
2016-06-14 14:11 ` Will Deacon
2016-06-14 15:04 ` Robin Murphy
2016-06-03 17:15 ` [PATCH v2 2/7] Docs: dt: add PCI IOMMU map bindings Robin Murphy
2016-06-14 14:16 ` Will Deacon
2016-06-03 17:15 ` [PATCH v2 3/7] of/irq: Break out msi-map lookup (again) Robin Murphy
2016-06-04 8:10 ` Marc Zyngier
2016-06-14 14:37 ` Will Deacon
2016-06-14 18:12 ` Robin Murphy
2016-06-14 18:20 ` Will Deacon
2016-06-14 17:01 ` Rob Herring
2016-06-15 10:16 ` Robin Murphy
2016-06-03 17:15 ` [PATCH v2 4/7] iommu/of: Handle iommu-map property for PCI Robin Murphy
2016-06-14 14:45 ` Will Deacon
2016-06-15 11:21 ` Robin Murphy
2016-06-03 17:15 ` [PATCH v2 5/7] iommu/arm-smmu: Implement of_xlate() for SMMUv3 Robin Murphy
2016-06-14 15:07 ` Will Deacon
2016-06-14 16:11 ` Robin Murphy
2016-06-03 17:15 ` [PATCH v2 6/7] iommu/arm-smmu: Finish off SMMUv3 default domain support Robin Murphy
2016-06-06 15:47 ` Jean-Philippe Brucker
2016-06-06 17:22 ` Robin Murphy
2016-06-14 15:59 ` Will Deacon [this message]
2016-06-03 17:15 ` [PATCH v2 7/7] iommu/arm-smmu: Support non-PCI devices with SMMUv3 Robin Murphy
2016-06-14 15:16 ` Will Deacon
2016-06-15 1:22 ` Leizhen (ThunderTown)
2016-06-17 1:54 ` Leizhen (ThunderTown)
2016-06-17 9:14 ` Robin Murphy
2016-06-21 8:36 ` Leizhen (ThunderTown)
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