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| author | Robin Murphy <robin.murphy@arm.com> | 2016-04-20 14:53:33 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2016-04-21 16:47:32 +0200 |
| commit | 9800699c645952da6a7399194d3e762b84cde3cd (patch) | |
| tree | 14365ce42655652ef3e4a990385745bcce1b91ff /drivers/iommu | |
| parent | 5f634956cc550768ebd75cf26fdba01044bc600e (diff) | |
| download | linux-9800699c645952da6a7399194d3e762b84cde3cd.tar.gz linux-9800699c645952da6a7399194d3e762b84cde3cd.tar.bz2 linux-9800699c645952da6a7399194d3e762b84cde3cd.zip | |
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.c | 8 |
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; /* |