1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 06d268abe951..c5c61cabd6e3 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -155,6 +155,7 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
         if (event == BUS_NOTIFY_ADD_DEVICE) {
                 for (tmp = dev; tmp; tmp = tmp->bus->self) {
                         level--;
+                        info->path[level].bus = tmp->bus->number;
                         info->path[level].device = PCI_SLOT(tmp->devfn);
                         info->path[level].function = PCI_FUNC(tmp->devfn);
                         if (pci_is_root_bus(tmp->bus))
@@ -177,17 +178,33 @@ static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus,
         int i;
 
         if (info->bus != bus)
-                return false;
+                goto fallback;
         if (info->level != count)
-                return false;
+                goto fallback;
 
         for (i = 0; i < count; i++) {
                 if (path[i].device != info->path[i].device ||
                     path[i].function != info->path[i].function)
-                        return false;
+                        goto fallback;
         }
 
         return true;
+
+fallback:
+
+        if (count != 1)
+                return false;
+
+        i = info->level - 1;
+        if (bus              == info->path[i].bus &&
+            path[0].device   == info->path[i].device &&
+            path[0].function == info->path[i].function) {
+                pr_info(FW_BUG "RMRR entry for device %02x:%02x.%x is broken - applying workaround\n",
+                        bus, path[0].device, path[0].function);
+                return true;
+        }
+
+        return false;
 }
 
 /* Return: > 0 if match found, 0 if no match found, < 0 if error happens */
@@ -247,7 +264,7 @@ int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment,
 
         for_each_active_dev_scope(devices, count, index, tmp)
                 if (tmp == &info->dev->dev) {
-                        rcu_assign_pointer(devices[index].dev, NULL);
+                        RCU_INIT_POINTER(devices[index].dev, NULL);
                         synchronize_rcu();
                         put_device(tmp);
                         return 1;