1 files changed, 42 insertions, 3 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index b8802ae4bcdb..8d6159426311 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2767,7 +2767,15 @@ static void *intel_alloc_coherent(struct device *hwdev, size_t size,
 
         size = PAGE_ALIGN(size);
         order = get_order(size);
-        flags &= ~(GFP_DMA | GFP_DMA32);
+
+        if (!iommu_no_mapping(hwdev))
+                flags &= ~(GFP_DMA | GFP_DMA32);
+        else if (hwdev->coherent_dma_mask < dma_get_required_mask(hwdev)) {
+                if (hwdev->coherent_dma_mask < DMA_BIT_MASK(32))
+                        flags |= GFP_DMA;
+                else
+                        flags |= GFP_DMA32;
+        }
 
         vaddr = (void *)__get_free_pages(flags, order);
         if (!vaddr)
@@ -3207,6 +3215,33 @@ static int __init init_iommu_sysfs(void)
 }
 #endif  /* CONFIG_PM */
 
+/*
+ * Here we only respond to action of unbound device from driver.
+ *
+ * Added device is not attached to its DMAR domain here yet. That will happen
+ * when mapping the device to iova.
+ */
+static int device_notifier(struct notifier_block *nb,
+                                  unsigned long action, void *data)
+{
+        struct device *dev = data;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct dmar_domain *domain;
+
+        domain = find_domain(pdev);
+        if (!domain)
+                return 0;
+
+        if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through)
+                domain_remove_one_dev_info(domain, pdev);
+
+        return 0;
+}
+
+static struct notifier_block device_nb = {
+        .notifier_call = device_notifier,
+};
+
 int __init intel_iommu_init(void)
 {
         int ret = 0;
@@ -3231,7 +3266,7 @@ int __init intel_iommu_init(void)
          * Check the need for DMA-remapping initialization now.
          * Above initialization will also be used by Interrupt-remapping.
          */
-        if (no_iommu || swiotlb || dmar_disabled)
+        if (no_iommu || dmar_disabled)
                 return -ENODEV;
 
         iommu_init_mempool();
@@ -3252,13 +3287,17 @@ int __init intel_iommu_init(void)
         "PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
 
         init_timer(&unmap_timer);
-        force_iommu = 1;
+#ifdef CONFIG_SWIOTLB
+        swiotlb = 0;
+#endif
         dma_ops = &intel_dma_ops;
 
         init_iommu_sysfs();
 
         register_iommu(&intel_iommu_ops);
 
+        bus_register_notifier(&pci_bus_type, &device_nb);
+
         return 0;
 }