+
+ return 0;
+}
+
+static void domain_remove_one_dev_info(struct dmar_domain *domain,
+ struct pci_dev *pdev);
+static int identity_mapping(struct pci_dev *pdev)
+{
+ struct device_domain_info *info;
+
+ if (likely(!iommu_identity_mapping))
+ return 0;
+
+
+ list_for_each_entry(info, &si_domain->devices, link)
+ if (info->dev == pdev)
+ return 1;
+ return 0;
+}
+
+static int domain_add_dev_info(struct dmar_domain *domain,
+ struct pci_dev *pdev,
+ int translation)
+{
+ struct device_domain_info *info;
+ unsigned long flags;
+ int ret;
+
+ info = alloc_devinfo_mem();
+ if (!info)
+ return -ENOMEM;
+
+ ret = domain_context_mapping(domain, pdev, translation);
+ if (ret) {
+ free_devinfo_mem(info);
+ return ret;
+ }
+
+ info->segment = pci_domain_nr(pdev->bus);
+ info->bus = pdev->bus->number;
+ info->devfn = pdev->devfn;
+ info->dev = pdev;
+ info->domain = domain;
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ list_add(&info->link, &domain->devices);
+ list_add(&info->global, &device_domain_list);
+ pdev->dev.archdata.iommu = info;
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+
+ return 0;
+}
+
+static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
+{
+ if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
+ return 1;
+
+ if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
+ return 1;
+
+ if (!(iommu_identity_mapping & IDENTMAP_ALL))
+ return 0;
+
+ /*
+ * We want to start off with all devices in the 1:1 domain, and
+ * take them out later if we find they can't access all of memory.
+ *
+ * However, we can't do this for PCI devices behind bridges,
+ * because all PCI devices behind the same bridge will end up
+ * with the same source-id on their transactions.
+ *
+ * Practically speaking, we can't change things around for these
+ * devices at run-time, because we can't be sure there'll be no
+ * DMA transactions in flight for any of their siblings.
+ *
+ * So PCI devices (unless they're on the root bus) as well as
+ * their parent PCI-PCI or PCIe-PCI bridges must be left _out_ of
+ * the 1:1 domain, just in _case_ one of their siblings turns out
+ * not to be able to map all of memory.
+ */
+ if (!pci_is_pcie(pdev)) {
+ if (!pci_is_root_bus(pdev->bus))
+ return 0;
+ if (pdev->class >> 8 == PCI_CLASS_BRIDGE_PCI)
+ return 0;
+ } else if (pdev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE)
+ return 0;
+
+ /*
+ * At boot time, we don't yet know if devices will be 64-bit capable.
+ * Assume that they will -- if they turn out not to be, then we can
+ * take them out of the 1:1 domain later.
+ */
+ if (!startup)
+ return pdev->dma_mask > DMA_BIT_MASK(32);
+
+ return 1;
+}
+
+static int __init iommu_prepare_static_identity_mapping(int hw)
+{
+ struct pci_dev *pdev = NULL;
+ int ret;
+
+ ret = si_domain_init(hw);
+ if (ret)
+ return -EFAULT;
+
+ for_each_pci_dev(pdev) {
+ if (iommu_should_identity_map(pdev, 1)) {
+ printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n",
+ hw ? "hardware" : "software", pci_name(pdev));
+
+ ret = domain_add_dev_info(si_domain, pdev,
+ hw ? CONTEXT_TT_PASS_THROUGH :
+ CONTEXT_TT_MULTI_LEVEL);
+ if (ret)
+ return ret;
+ }
+ }
+