1 files changed, 38 insertions, 15 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797609b3..a673c7f7e208 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1940,13 +1940,32 @@ void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
 }
 EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
 
+static int __arm_iommu_attach_device(struct device *dev,
+                                     struct dma_iommu_mapping *mapping)
+{
+        int err;
+
+        err = iommu_attach_device(mapping->domain, dev);
+        if (err)
+                return err;
+
+        kref_get(&mapping->kref);
+        dev->archdata.mapping = mapping;
+
+        pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
+        return 0;
+}
+
 /**
  * arm_iommu_attach_device
  * @dev: valid struct device pointer
  * @mapping: io address space mapping structure (returned from
  *      arm_iommu_create_mapping)
  *
- * Attaches specified io address space mapping to the provided device,
+ * Attaches specified io address space mapping to the provided device.
+ * This replaces the dma operations (dma_map_ops pointer) with the
+ * IOMMU aware version.
+ *
  * More than one client might be attached to the same io address space
  * mapping.
  */
@@ -1955,25 +1974,16 @@ int arm_iommu_attach_device(struct device *dev,
 {
         int err;
 
-        err = iommu_attach_device(mapping->domain, dev);
+        err = __arm_iommu_attach_device(dev, mapping);
         if (err)
                 return err;
 
-        kref_get(&mapping->kref);
-        dev->archdata.mapping = mapping;
-
-        pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
+        set_dma_ops(dev, &iommu_ops);
         return 0;
 }
 EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
 
-/**
- * arm_iommu_detach_device
- * @dev: valid struct device pointer
- *
- * Detaches the provided device from a previously attached map.
- */
-void arm_iommu_detach_device(struct device *dev)
+static void __arm_iommu_detach_device(struct device *dev)
 {
         struct dma_iommu_mapping *mapping;
 
@@ -1989,6 +1999,19 @@ void arm_iommu_detach_device(struct device *dev)
 
         pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
 }
+
+/**
+ * arm_iommu_detach_device
+ * @dev: valid struct device pointer
+ *
+ * Detaches the provided device from a previously attached map.
+ * This voids the dma operations (dma_map_ops pointer)
+ */
+void arm_iommu_detach_device(struct device *dev)
+{
+        __arm_iommu_detach_device(dev);
+        set_dma_ops(dev, NULL);
+}
 EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
 
 static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
@@ -2011,7 +2034,7 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
                 return false;
         }
 
-        if (arm_iommu_attach_device(dev, mapping)) {
+        if (__arm_iommu_attach_device(dev, mapping)) {
                 pr_warn("Failed to attached device %s to IOMMU_mapping\n",
                                 dev_name(dev));
                 arm_iommu_release_mapping(mapping);
@@ -2025,7 +2048,7 @@ static void arm_teardown_iommu_dma_ops(struct device *dev)
 {
         struct dma_iommu_mapping *mapping = dev->archdata.mapping;
 
-        arm_iommu_detach_device(dev);
+        __arm_iommu_detach_device(dev);
         arm_iommu_release_mapping(mapping);
 }