1 files changed, 35 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index ef9b309e8e09..2f7c0b3a448b 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1683,4 +1683,39 @@ static void amd_iommu_detach_device(struct iommu_domain *dom,
         iommu_completion_wait(iommu);
 }
 
+static int amd_iommu_attach_device(struct iommu_domain *dom,
+                                   struct device *dev)
+{
+        struct protection_domain *domain = dom->priv;
+        struct protection_domain *old_domain;
+        struct amd_iommu *iommu;
+        struct pci_dev *pdev;
+        u16 devid;
+
+        if (dev->bus != &pci_bus_type)
+                return -EINVAL;
+
+        pdev = to_pci_dev(dev);
+
+        devid = calc_devid(pdev->bus->number, pdev->devfn);
+
+        if (devid >= amd_iommu_last_bdf ||
+                        devid != amd_iommu_alias_table[devid])
+                return -EINVAL;
+
+        iommu = amd_iommu_rlookup_table[devid];
+        if (!iommu)
+                return -EINVAL;
+
+        old_domain = domain_for_device(devid);
+        if (old_domain)
+                return -EBUSY;
+
+        attach_device(iommu, domain, devid);
+
+        iommu_completion_wait(iommu);
+
+        return 0;
+}
+
 #endif