iommu/vt-d: Introduce is_downstream_to_pci_bridge helper

	return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;

}

/**

 * is_downstream_to_pci_bridge - test if a device belongs to the PCI

 *				 sub-hierarchy of a candidate PCI-PCI bridge

 * @dev: candidate PCI device belonging to @bridge PCI sub-hierarchy

 * @bridge: the candidate PCI-PCI bridge

 *

 * Return: true if @dev belongs to @bridge PCI sub-hierarchy, else false.

 */

static bool

is_downstream_to_pci_bridge(struct device *dev, struct device *bridge)

{

	struct pci_dev *pdev, *pbridge;

	if (!dev_is_pci(dev) || !dev_is_pci(bridge))

		return false;

	pdev = to_pci_dev(dev);

	pbridge = to_pci_dev(bridge);

	if (pbridge->subordinate &&

	    pbridge->subordinate->number <= pdev->bus->number &&

	    pbridge->subordinate->busn_res.end >= pdev->bus->number)

		return true;

	return false;

}

static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)

{

	struct dmar_drhd_unit *drhd = NULL;

	struct intel_iommu *iommu;

	struct device *tmp;

	struct pci_dev *ptmp, *pdev = NULL;

	struct pci_dev *pdev = NULL;

	u16 segment = 0;

	int i;

				goto out;

			}

			if (!pdev || !dev_is_pci(tmp))

				continue;

			ptmp = to_pci_dev(tmp);

			if (ptmp->subordinate &&

			    ptmp->subordinate->number <= pdev->bus->number &&

			    ptmp->subordinate->busn_res.end >= pdev->bus->number)

			if (is_downstream_to_pci_bridge(dev, tmp))

				goto got_pdev;

		}