Merge tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / iommu / intel-iommu.c

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 9476c1b96090de200dd3f48dee23dc080653c971..c2c07a4a7f21c5f57d9eca2884933dd99088b60a 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2327,8 +2327,39 @@ 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;