As domain->force_snooping only impacts the devices attached with the domain, there's no need to check against all IOMMU units. At the same time, for a brand new domain (hasn't been attached to any device), the force_snooping field could be set, but the attach_dev callback will return failure if it wants to attach to a device which IOMMU has no snoop control capability.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com> --- include/linux/intel-iommu.h | 1 + drivers/iommu/intel/pasid.h | 2 ++ drivers/iommu/intel/iommu.c | 51 ++++++++++++++++++++++++++++++++++--- drivers/iommu/intel/pasid.c | 23 +++++++++++++++++ 4 files changed, 74 insertions(+), 3 deletions(-) diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 72e5d7900e71..4f29139bbfc3 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -540,6 +540,7 @@ struct dmar_domain { u8 has_iotlb_device: 1; u8 iommu_coherency: 1; /* indicate coherency of iommu access */ u8 force_snooping : 1; /* Create IOPTEs with snoop control */ + u8 set_pte_snp:1; struct list_head devices; /* all devices' list */ struct iova_domain iovad; /* iova's that belong to this domain */ diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h index ab4408c824a5..583ea67fc783 100644 --- a/drivers/iommu/intel/pasid.h +++ b/drivers/iommu/intel/pasid.h @@ -123,4 +123,6 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, bool fault_ignore); int vcmd_alloc_pasid(struct intel_iommu *iommu, u32 *pasid); void vcmd_free_pasid(struct intel_iommu *iommu, u32 pasid); +void intel_pasid_setup_page_snoop_control(struct intel_iommu *iommu, + struct device *dev, u32 pasid); #endif /* __INTEL_PASID_H */ diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index d68f5bbf3e93..98112228ae93 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2459,7 +2459,7 @@ static int domain_setup_first_level(struct intel_iommu *iommu, if (level == 5) flags |= PASID_FLAG_FL5LP; - if (domain->domain.type == IOMMU_DOMAIN_UNMANAGED) + if (domain->force_snooping) flags |= PASID_FLAG_PAGE_SNOOP; return intel_pasid_setup_first_level(iommu, dev, (pgd_t *)pgd, pasid, @@ -4431,7 +4431,7 @@ static int intel_iommu_map(struct iommu_domain *domain, prot |= DMA_PTE_READ; if (iommu_prot & IOMMU_WRITE) prot |= DMA_PTE_WRITE; - if (dmar_domain->force_snooping) + if (dmar_domain->set_pte_snp) prot |= DMA_PTE_SNP; max_addr = iova + size; @@ -4554,13 +4554,58 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, return phys; } +static bool domain_support_force_snooping(struct dmar_domain *domain) +{ + struct device_domain_info *info; + unsigned long flags; + bool support = true; + + spin_lock_irqsave(&device_domain_lock, flags); + list_for_each_entry(info, &domain->devices, link) { + if (!ecap_sc_support(info->iommu->ecap)) { + support = false; + break; + } + } + spin_unlock_irqrestore(&device_domain_lock, flags); + + return support; +} + +static void domain_set_force_snooping(struct dmar_domain *domain) +{ + struct device_domain_info *info; + unsigned long flags; + + /* + * Second level page table supports per-PTE snoop control. The + * iommu_map() interface will handle this by setting SNP bit. + */ + if (!domain_use_first_level(domain)) { + domain->set_pte_snp = true; + return; + } + + spin_lock_irqsave(&device_domain_lock, flags); + list_for_each_entry(info, &domain->devices, link) + intel_pasid_setup_page_snoop_control(info->iommu, info->dev, + PASID_RID2PASID); + spin_unlock_irqrestore(&device_domain_lock, flags); +} + static bool intel_iommu_enforce_cache_coherency(struct iommu_domain *domain) { struct dmar_domain *dmar_domain = to_dmar_domain(domain); - if (!domain_update_iommu_snooping(NULL)) + if (dmar_domain->force_snooping) + return true; + + if (!domain_support_force_snooping(dmar_domain)) return false; + + domain_set_force_snooping(dmar_domain); dmar_domain->force_snooping = true; + return true; } diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index f8d215d85695..41a0e3b02c79 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -762,3 +762,26 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu, return 0; } + +/* + * Set the page snoop control for a pasid entry which has been set up. + */ +void intel_pasid_setup_page_snoop_control(struct intel_iommu *iommu, + struct device *dev, u32 pasid) +{ + struct pasid_entry *pte; + u16 did; + + spin_lock(&iommu->lock); + pte = intel_pasid_get_entry(dev, pasid); + if (WARN_ON(!pte || !pasid_pte_is_present(pte))) { + spin_unlock(&iommu->lock); + return; + } + + pasid_set_pgsnp(pte); + did = pasid_get_domain_id(pte); + spin_unlock(&iommu->lock); + + pasid_flush_caches(iommu, pte, pasid, did); +} -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu