Hi Will, On 04/15/2016 03:05 PM, Will Deacon wrote: > On Wed, Apr 13, 2016 at 03:46:57PM +0100, Robin Murphy wrote: >> 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. > > Eric, does this resolve your remaining passthrough regressions when applied > on top of my patch?
Yes it does. Thank you for the fixes. Best Regards Eric > > Will > >> Reported-by: Eric Auger <[email protected]> >> Signed-off-by: Robin Murphy <[email protected]> >> --- >> drivers/iommu/arm-smmu.c | 8 +++++++- >> 1 file changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >> index 5158feb..7c39ac4 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; >> >> /* >> -- >> 2.7.3.dirty >> _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
