arch/powerpc/platforms/pseries/iommu.c | 36 +++++++++++++-------------
  1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 712d1667144a..b34b473bbdc1 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c

@@ -853,25 +853,26 @@ static void remove_ddw(struct device_node *np, bool remove_prop)
  			np, ret);
  }
  
-static u64 find_existing_ddw(struct device_node *pdn, int *window_shift)
+static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr, int *window_shift)
  {
  	struct direct_window *window;
  	const struct dynamic_dma_window_prop *direct64;
-	u64 dma_addr = 0;
+	bool found = false;
  
  	spin_lock(&direct_window_list_lock);
  	/* check if we already created a window and dupe that config if so */
  	list_for_each_entry(window, &direct_window_list, list) {
  		if (window->device == pdn) {
  			direct64 = window->prop;
-			dma_addr = be64_to_cpu(direct64->dma_base);
+			*dma_addr = be64_to_cpu(direct64->dma_base);
  			*window_shift = be32_to_cpu(direct64->window_shift);
+			found = true;
  			break;
  		}
  	}
  	spin_unlock(&direct_window_list_lock);
  
-	return dma_addr;
+	return found;
  }
  
  static struct direct_window *ddw_list_new_entry(struct device_node *pdn,

@@ -1161,20 +1162,20 @@ static int iommu_get_page_shift(u32 query_page_size)
   * pdn: the parent pe node with the ibm,dma_window property
   * Future: also check if we can remap the base window for our base page size
   *
- * returns the dma offset for use by the direct mapped DMA code.
+ * returns true if can map all pages (direct mapping), false otherwise..
   */
-static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
+static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
  {
  	int len = 0, ret;
  	int max_ram_len = order_base_2(ddw_memory_hotplug_max());
  	struct ddw_query_response query;
  	struct ddw_create_response create;
  	int page_shift;
-	u64 dma_addr;
  	struct device_node *dn;
  	u32 ddw_avail[DDW_APPLICABLE_SIZE];
  	struct direct_window *window;
  	struct property *win64;
+	bool ddw_enabled = false;
  	struct dynamic_dma_window_prop *ddwprop;
  	struct failed_ddw_pdn *fpdn;
  	bool default_win_removed = false;

@@ -1186,9 +1187,10 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
  
  	mutex_lock(&direct_window_init_mutex);
  
-	dma_addr = find_existing_ddw(pdn, &len);
-	if (dma_addr != 0)
+	if (find_existing_ddw(pdn, &dev->dev.archdata.dma_offset, &len)) {
+		ddw_enabled = true;
  		goto out_unlock;
+	}
  
  	/*
  	 * If we already went through this for a previous function of

@@ -1342,7 +1344,8 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
  	list_add(&window->list, &direct_window_list);
  	spin_unlock(&direct_window_list_lock);
  
-	dma_addr = be64_to_cpu(ddwprop->dma_base);
+	dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
+	ddw_enabled = true;
  	goto out_unlock;
  
  out_free_window:

@@ -1374,10 +1377,10 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
  	 * as RAM, then we failed to create a window to cover persistent
  	 * memory and need to set the DMA limit.
  	 */
-	if (pmem_present && dma_addr && (len == max_ram_len))
-		dev->dev.bus_dma_limit = dma_addr + (1ULL << len);
+	if (pmem_present && ddw_enabled && (len == max_ram_len))
+		dev->dev.bus_dma_limit = dev->dev.archdata.dma_offset + (1ULL << len);
  
-	return dma_addr;
+	return ddw_enabled;
  }
  
  static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)

@@ -1456,11 +1459,8 @@ static bool iommu_bypass_supported_pSeriesLP(struct pci_dev *pdev, u64 dma_mask)
  			break;
  	}
  
-	if (pdn && PCI_DN(pdn)) {
-		pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn);
-		if (pdev->dev.archdata.dma_offset)
-			return true;
-	}
+	if (pdn && PCI_DN(pdn))
+		return enable_ddw(pdev, pdn);
  
  	return false;
  }