iommu/dma: move the arm64 wrappers to common code

There is nothing really arm64 specific in the iommu_dma_ops
implementation, so move it to dma-iommu.c and keep a lot of symbols
self-contained.  Note the implementation does depend on the
DMA_DIRECT_REMAP infrastructure for now, so we'll have to make the
DMA_IOMMU support depend on it, but this will be relaxed soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -97,6 +97,7 @@ config IOMMU_DMA
 	select IOMMU_IOVA
 	select IRQ_MSI_IOMMU
 	select NEED_SG_DMA_LENGTH
+	depends on DMA_DIRECT_REMAP
 
 config FSL_PAMU
 	bool "Freescale IOMMU support"

include/linux/dma-iommu.h

@@ -24,49 +24,13 @@
 #include <linux/iommu.h>
 #include <linux/msi.h>
 
-int iommu_dma_init(void);
-
 /* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
 int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
 /* Setup call for arch DMA mapping code */
-int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
-		u64 size, struct device *dev);
-
-/* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
-		     unsigned long attrs);
-
-/*
- * These implement the bulk of the relevant DMA mapping callbacks, but require
- * the arch code to take care of attributes and cache maintenance
- */
-struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
-		unsigned long attrs, int prot, dma_addr_t *handle);
-void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
-		dma_addr_t *handle);
-
-int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
-
-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
-		unsigned long offset, size_t size, int prot);
-int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
-		int nents, int prot);
-
-/*
- * Arch code with no special attribute handling may use these
- * directly as DMA mapping callbacks for simplicity
- */
-void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
-		enum dma_data_direction dir, unsigned long attrs);
-void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
-		enum dma_data_direction dir, unsigned long attrs);
-dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
-		size_t size, enum dma_data_direction dir, unsigned long attrs);
-void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
-		size_t size, enum dma_data_direction dir, unsigned long attrs);
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size);
 
 /* The DMA API isn't _quite_ the whole story, though... */
 /*
@@ -91,9 +55,9 @@ struct msi_desc;
 struct msi_msg;
 struct device;
 
-static inline int iommu_dma_init(void)
+static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
+		u64 size)
 {
-	return 0;
 }
 
 static inline int iommu_get_dma_cookie(struct iommu_domain *domain)