From: Joerg Roedel <jroe...@suse.de> Cc: Will Deacon <will.dea...@arm.com> Signed-off-by: Joerg Roedel <jroe...@suse.de> --- drivers/iommu/arm-smmu.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index ca18d6d..47c2cb6 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1515,20 +1515,37 @@ static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain, return __pfn_to_phys(pte_pfn(pte)) | (iova & ~PAGE_MASK); } -static int arm_smmu_domain_has_cap(struct iommu_domain *domain, - unsigned long cap) +static bool arm_smmu_capable(enum iommu_cap cap) { - struct arm_smmu_domain *smmu_domain = domain->priv; - struct arm_smmu_device *smmu = smmu_domain->smmu; - u32 features = smmu ? smmu->features : 0; + struct arm_smmu_device *smmu; + bool ret = false; switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: - return features & ARM_SMMU_FEAT_COHERENT_WALK; + /* + * Use ARM_SMMU_FEAT_COHERENT_WALK as an indicator on whether + * the SMMU can force coherency on the DMA transaction. If it + * supports COHERENT_WALK it must be behind a coherent + * interconnect. + * A domain can be attached to any SMMU, so to reliably support + * IOMMU_CAP_CACHE_COHERENCY all SMMUs in the system need to be + * behind a coherent interconnect. + */ + spin_lock(&arm_smmu_devices_lock); + list_for_each_entry(smmu, &arm_smmu_devices, list) { + if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK) { + ret = true; + } else { + ret = false; + break; + } + } + spin_unlock(&arm_smmu_devices_lock); + return ret; case IOMMU_CAP_INTR_REMAP: - return 1; /* MSIs are just memory writes */ + return true; /* MSIs are just memory writes */ default: - return 0; + return false; } } @@ -1598,6 +1615,7 @@ static void arm_smmu_remove_device(struct device *dev) } static const struct iommu_ops arm_smmu_ops = { + .capable = arm_smmu_capable, .domain_init = arm_smmu_domain_init, .domain_destroy = arm_smmu_domain_destroy, .attach_dev = arm_smmu_attach_dev, @@ -1605,7 +1623,6 @@ static const struct iommu_ops arm_smmu_ops = { .map = arm_smmu_map, .unmap = arm_smmu_unmap, .iova_to_phys = arm_smmu_iova_to_phys, - .domain_has_cap = arm_smmu_domain_has_cap, .add_device = arm_smmu_add_device, .remove_device = arm_smmu_remove_device, .pgsize_bitmap = (SECTION_SIZE | -- 1.9.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu