1 files changed, 12 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/dma_64.c b/arch/powerpc/kernel/dma_64.c
index 14206e3f0819..84239076a5b8 100644
--- a/arch/powerpc/kernel/dma_64.c
+++ b/arch/powerpc/kernel/dma_64.c
@@ -112,10 +112,16 @@ EXPORT_SYMBOL(dma_iommu_ops);
 /*
  * Generic direct DMA implementation
  *
- * This implementation supports a global offset that can be applied if
- * the address at which memory is visible to devices is not 0.
+ * This implementation supports a per-device offset that can be applied if
+ * the address at which memory is visible to devices is not 0. Platform code
+ * can set archdata.dma_data to an unsigned long holding the offset. By
+ * default the offset is zero.
  */
-unsigned long dma_direct_offset;
+
+static unsigned long get_dma_direct_offset(struct device *dev)
+{
+        return (unsigned long)dev->archdata.dma_data;
+}
 
 static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
                                        dma_addr_t *dma_handle, gfp_t flag)
@@ -124,13 +130,12 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
         void *ret;
         int node = dev->archdata.numa_node;
 
-        /* TODO: Maybe use the numa node here too ? */
         page = alloc_pages_node(node, flag, get_order(size));
         if (page == NULL)
                 return NULL;
         ret = page_address(page);
         memset(ret, 0, size);
-        *dma_handle = virt_to_abs(ret) | dma_direct_offset;
+        *dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
 
         return ret;
 }
@@ -145,7 +150,7 @@ static dma_addr_t dma_direct_map_single(struct device *dev, void *ptr,
                                         size_t size,
                                         enum dma_data_direction direction)
 {
-        return virt_to_abs(ptr) | dma_direct_offset;
+        return virt_to_abs(ptr) + get_dma_direct_offset(dev);
 }
 
 static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
@@ -161,7 +166,7 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
         int i;
 
         for_each_sg(sgl, sg, nents, i) {
-                sg->dma_address = sg_phys(sg) | dma_direct_offset;
+                sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
                 sg->dma_length = sg->length;
         }