intel-iommu: Prevent devices with RMRRs from being placed into SI Domain

[pandora-kernel.git] / drivers / iommu / intel-iommu.c

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6c886cd..dffdca8 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2302,8 +2302,39 @@ static int domain_add_dev_info(struct dmar_domain *domain,
        return 0;
 }
 
+static bool device_has_rmrr(struct pci_dev *dev)
+{
+       struct dmar_rmrr_unit *rmrr;
+       int i;
+
+       for_each_rmrr_units(rmrr) {
+               for (i = 0; i < rmrr->devices_cnt; i++) {
+                       /*
+                        * Return TRUE if this RMRR contains the device that
+                        * is passed in.
+                        */
+                       if (rmrr->devices[i] == dev)
+                               return true;
+               }
+       }
+       return false;
+}
+
 static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
 {
+
+       /*
+        * We want to prevent any device associated with an RMRR from
+        * getting placed into the SI Domain. This is done because
+        * problems exist when devices are moved in and out of domains
+        * and their respective RMRR info is lost. We exempt USB devices
+        * from this process due to their usage of RMRRs that are known
+        * to not be needed after BIOS hand-off to OS.
+        */
+       if (device_has_rmrr(pdev) &&
+           (pdev->class >> 8) != PCI_CLASS_SERIAL_USB)
+               return 0;
+
        if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
                return 1;