[PATCH 1/3] powerpc/iommu: Remove dma_data union

[Benjamin Herrenschmidt]

To support "hybrid" DMA ops in a subsequent patch, we will need both
a direct DMA offset and an iommu pointer. Those are currently exclusive
(a union), so change them to be separate fields.

While there, also type iommu_table_base properly and make exist only
on CONFIG_PPC64 since it's not referenced on 32-bit at all.

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
 arch/powerpc/include/asm/device.h      | 15 +++++++++------
 arch/powerpc/include/asm/dma-mapping.h |  4 ++--
 arch/powerpc/include/asm/iommu.h       | 31 +++++++++++++++++++++++++------
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 9f1371b..9ce2199 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -10,6 +10,7 @@ struct dma_map_ops;
 struct device_node;
 #ifdef CONFIG_PPC64
 struct pci_dn;
+struct iommu_table;
 #endif
 
 /*
@@ -23,13 +24,15 @@ struct dev_archdata {
 	struct dma_map_ops	*dma_ops;
 
 	/*
-	 * 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.
+	 * These two used to be a union. However, with the hybrid ops we need
+	 * both so here we store both a DMA offset for direct mappings and
+	 * an iommu_table for remapped DMA.
 	 */
-	union {
-		dma_addr_t	dma_offset;
-		void		*iommu_table_base;
-	} dma_data;
+	dma_addr_t		dma_offset;
+
+#ifdef CONFIG_PPC64
+	struct iommu_table	*iommu_table_base;
+#endif
 
 #ifdef CONFIG_IOMMU_API
 	void			*iommu_domain;
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 894d538..35b9965 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -106,7 +106,7 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
 static inline dma_addr_t get_dma_offset(struct device *dev)
 {
 	if (dev)
-		return dev->archdata.dma_data.dma_offset;
+		return dev->archdata.dma_offset;
 
 	return PCI_DRAM_OFFSET;
 }
@@ -114,7 +114,7 @@ static inline dma_addr_t get_dma_offset(struct device *dev)
 static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 {
 	if (dev)
-		dev->archdata.dma_data.dma_offset = off;
+		dev->archdata.dma_offset = off;
 }
 
 /* this will be removed soon */
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index e2abbe8..e67e678 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -93,16 +93,21 @@ int get_iommu_order(unsigned long size, struct iommu_table *tbl)
 
 struct scatterlist;
 
-static inline void set_iommu_table_base(struct device *dev, void *base)
+#ifdef CONFIG_PPC64
+
+static inline void set_iommu_table_base(struct device *dev,
+					struct iommu_table *base)
 {
-	dev->archdata.dma_data.iommu_table_base = base;
+	dev->archdata.iommu_table_base = base;
 }
 
 static inline void *get_iommu_table_base(struct device *dev)
 {
-	return dev->archdata.dma_data.iommu_table_base;
+	return dev->archdata.iommu_table_base;
 }
 
+extern int dma_iommu_dma_supported(struct device *dev, u64 mask);
+
 /* Frees table for an individual device node */
 extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
 
@@ -146,6 +151,20 @@ static inline void set_iommu_table_base_and_group(struct device *dev,
 	iommu_add_device(dev);
 }
 
+#else
+
+static inline void *get_iommu_table_base(struct device *dev)
+{
+	return NULL;
+}
+
+static inline int dma_iommu_dma_supported(struct device *dev, u64 mask)
+{
+	return 0;
+}
+
+#endif /* CONFIG_PPC64 */
+
 extern int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl,
 			    struct scatterlist *sglist, int nelems,
 			    unsigned long mask,