Hi Sunil, On Tue, Apr 25, 2017 at 03:27:52PM +0530, sunil.kovv...@gmail.com wrote: > From: Sunil Goutham <sgout...@cavium.com> > > For software initiated address translation, when domain type is > IOMMU_DOMAIN_IDENTITY i.e SMMU is bypassed, mimic HW behavior > i.e return the same IOVA as translated address. > > This patch is an extension to Will Deacon's patchset > "Implement SMMU passthrough using the default domain". > > Signed-off-by: Sunil Goutham <sgout...@cavium.com> > --- > > V2 > - As per Will's suggestion applied fix to SMMUv3 driver as well.
This follows what the AMD driver does, so: Acked-by: Will Deacon <will.dea...@arm.com> but I still think that having drivers/net/ethernet/cavium/thunder/nicvf_queues.c poke around with the physical address to get at the struct pages underlying a DMA buffer is really dodgy. Is there no way this can be avoided, perhaps by tracking the pages some other way (although I don't understand why you're having to mess with the page reference counts to start with)? At least, I think you should be checking the domain type in nicvf_iova_to_phys, which clearly expects a DMA domain if one exists at all. Joerg: sorry, this is another one for you to pick up if possible. Cheers, Will > drivers/iommu/arm-smmu-v3.c | 3 +++ > drivers/iommu/arm-smmu.c | 3 +++ > 2 files changed, 6 insertions(+) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 05b4592..d412bdd 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -1714,6 +1714,9 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, > dma_addr_t iova) > struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); > struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops; > > + if (domain->type == IOMMU_DOMAIN_IDENTITY) > + return iova; > + > if (!ops) > return 0; > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index bfab4f7..81088cd 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1459,6 +1459,9 @@ static phys_addr_t arm_smmu_iova_to_phys(struct > iommu_domain *domain, > struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); > struct io_pgtable_ops *ops= smmu_domain->pgtbl_ops; > > + if (domain->type == IOMMU_DOMAIN_IDENTITY) > + return iova; > + > if (!ops) > return 0; > > -- > 2.7.4 > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
