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authorRobin Murphy <robin.murphy@arm.com>2016-04-20 14:53:33 +0100
committerJoerg Roedel <jroedel@suse.de>2016-04-21 16:47:32 +0200
commit9800699c645952da6a7399194d3e762b84cde3cd (patch)
tree14365ce42655652ef3e4a990385745bcce1b91ff /drivers/iommu
parent5f634956cc550768ebd75cf26fdba01044bc600e (diff)
iommu/arm-smmu: Don't allocate resources for bypass domains
Until we get fully plumbed into of_iommu_configure, our default IOMMU_DOMAIN_DMA domains just bypass translation. Since we achieve that by leaving the stream table entries set to bypass instead of pointing at a translation context, the context bank we allocate for the domain is completely wasted. Context banks are typically a rather limited resource, so don't hog ones we don't need. Reported-by: Eric Auger <eric.auger@linaro.org> Tested-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/arm-smmu.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5158febd889d..7c39ac4b9c53 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -826,6 +826,12 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
if (smmu_domain->smmu)
goto out_unlock;
+ /* We're bypassing these SIDs, so don't allocate an actual context */
+ if (domain->type == IOMMU_DOMAIN_DMA) {
+ smmu_domain->smmu = smmu;
+ goto out_unlock;
+ }
+
/*
* Mapping the requested stage onto what we support is surprisingly
* complicated, mainly because the spec allows S1+S2 SMMUs without
@@ -948,7 +954,7 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
void __iomem *cb_base;
int irq;
- if (!smmu)
+ if (!smmu || domain->type == IOMMU_DOMAIN_DMA)
return;
/*