diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 2aa7afd90c3e..8662f5c10721 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -3693,7 +3693,31 @@ static void intel_iommu_free_dmars(void) } } -int dmar_find_matched_atsr_unit(struct pci_dev *dev) +static struct dmar_satc_unit *dmar_find_matched_satc_unit(struct pci_dev *dev) +{ + struct dmar_satc_unit *satcu; + struct acpi_dmar_satc *satc; + struct device *tmp; + int i; + + dev = pci_physfn(dev); + rcu_read_lock(); + + list_for_each_entry_rcu(satcu, &dmar_satc_units, list) { + satc = container_of(satcu->hdr, struct acpi_dmar_satc, header); + if (satc->segment != pci_domain_nr(dev->bus)) + continue; + for_each_dev_scope(satcu->devices, satcu->devices_cnt, i, tmp) + if (to_pci_dev(tmp) == dev) + goto out; + } + satcu = NULL; +out: + rcu_read_unlock(); + return satcu; +} + +static int dmar_ats_supported(struct pci_dev *dev, struct intel_iommu *iommu) { int i, ret = 1; struct pci_bus *bus; @@ -3701,8 +3725,20 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev) struct device *tmp; struct acpi_dmar_atsr *atsr; struct dmar_atsr_unit *atsru; + struct dmar_satc_unit *satcu; dev = pci_physfn(dev); + satcu = dmar_find_matched_satc_unit(dev); + if (satcu) + /* + * This device supports ATS as it is in SATC table. + * When IOMMU is in legacy mode, enabling ATS is done + * automatically by HW for the device that requires + * ATS, hence OS should not enable this device ATS + * to avoid duplicated TLB invalidation. + */ + return !(satcu->atc_required && !sm_supported(iommu)); + for (bus = dev->bus; bus; bus = bus->parent) { bridge = bus->self; /* If it's an integrated device, allow ATS */ @@ -4550,7 +4586,7 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) if (dev_is_pci(dev)) { if (ecap_dev_iotlb_support(iommu->ecap) && pci_ats_supported(pdev) && - dmar_find_matched_atsr_unit(pdev)) + dmar_ats_supported(pdev, iommu)) info->ats_supported = 1; if (sm_supported(iommu)) { |