powerpc: Change archdata dma_data to a union

Sometimes this is used to hold a simple offset, and sometimes
it is used to hold a pointer.  This patch changes it to a union containing
void * and dma_addr_t.  get/set accessors are also provided, because it was
getting a bit ugly to get to the actual data.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 28 insertions, 3 deletions

diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 9dade15d1ab..6d94d27ed85 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -15,7 +15,16 @@ struct dev_archdata {
 
         /* DMA operations on that device */
         struct dma_map_ops      *dma_ops;
-        void                    *dma_data;
+
+        /*
+         * When an iommu is in use, dma_data is used as a ptr to the base of the
+         * iommu_table.  Otherwise, it is a simple numerical offset.
+         */
+        union {
+                dma_addr_t      dma_offset;
+                void            *iommu_table_base;
+        } dma_data;
+
 #ifdef CONFIG_SWIOTLB
         dma_addr_t              max_direct_dma_addr;
 #endif
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 34b919fe8cd..e281daebddc 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -97,14 +97,20 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
  * swiotlb use this function, but it is typically not used by implementations
  * with an iommu.
  */
-static inline unsigned long get_dma_offset(struct device *dev)
+static inline dma_addr_t get_dma_offset(struct device *dev)
 {
         if (dev)
-                return (unsigned long)dev->archdata.dma_data;
+                return dev->archdata.dma_data.dma_offset;
 
         return PCI_DRAM_OFFSET;
 }
 
+static inline void set_dma_offset(struct device *dev, dma_addr_t off)
+{
+        if (dev)
+                dev->archdata.dma_data.dma_offset = off;
+}
+
 /* this will be removed soon */
 #define flush_write_buffers()
 
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 7464c0daddd..edfc9803ec9 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -70,6 +70,16 @@ struct iommu_table {
 
 struct scatterlist;
 
+static inline void set_iommu_table_base(struct device *dev, void *base)
+{
+        dev->archdata.dma_data.iommu_table_base = base;
+}
+
+static inline void *get_iommu_table_base(struct device *dev)
+{
+        return dev->archdata.dma_data.iommu_table_base;
+}
+
 /* Frees table for an individual device node */
 extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);