arm64: Assume the DMA is coherent and simplify the API implementation

The initial code was using swiotlb but assuming that the DMA is not
coherent. Until we get a platform that needs this, just assume that the
DMA is coherent and simplify the default DMA API implementation.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 9 insertions, 141 deletions

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 4e5871dd8b4..5b197ec57cf 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -33,159 +33,27 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
 					  dma_addr_t *dma_handle, gfp_t flags,
 					  struct dma_attrs *attrs)
 {
-	struct page *page, **map;
-	void *ptr;
-	int order = get_order(size);
-	int i;
-
-	if (dev->coherent_dma_mask != DMA_BIT_MASK(64))
-		flags |= GFP_DMA;
-
-	ptr = swiotlb_alloc_coherent(dev, size, dma_handle, flags);
-	if (!ptr)
-		goto no_mem;
-	map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA);
-	if (!map)
-		goto no_map;
-
-	/* remove any dirty cache lines on the kernel alias */
-	dmac_flush_range(ptr, ptr + size);
-
-	/* create a coherent mapping */
-	page = virt_to_page(ptr);
-	for (i = 0; i < (size >> PAGE_SHIFT); i++)
-		map[i] = page + i;
-	ptr = vmap(map, size >> PAGE_SHIFT, VM_MAP,
-		   pgprot_dmacoherent(pgprot_default)); kfree(map);
-	if (!ptr)
-		goto no_map;
-
-	return ptr;
-
-no_map:
-	swiotlb_free_coherent(dev, size, ptr, *dma_handle);
-no_mem:
-	*dma_handle = ~0;
-	return NULL;
+	return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
 }
 
 static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
 					void *vaddr, dma_addr_t dma_handle,
 					struct dma_attrs *attrs)
 {
-	vunmap(vaddr);
 	swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 }
 
-static dma_addr_t arm64_swiotlb_map_page(struct device *dev,
-					 struct page *page,
-					 unsigned long offset, size_t size,
-					 enum dma_data_direction dir,
-					 struct dma_attrs *attrs)
-{
-	dma_addr_t dev_addr;
-
-	dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
-	dmac_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
-
-	return dev_addr;
-}
-
-
-static void arm64_swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
-				     size_t size, enum dma_data_direction dir,
-				     struct dma_attrs *attrs)
-{
-	dmac_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
-	swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
-}
-
-static int arm64_swiotlb_map_sg_attrs(struct device *dev,
-				      struct scatterlist *sgl, int nelems,
-				      enum dma_data_direction dir,
-				      struct dma_attrs *attrs)
-{
-	struct scatterlist *sg;
-	int i, ret;
-
-	ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
-	for_each_sg(sgl, sg, ret, i)
-		dmac_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
-			      sg->length, dir);
-
-	return ret;
-}
-
-static void arm64_swiotlb_unmap_sg_attrs(struct device *dev,
-					 struct scatterlist *sgl, int nelems,
-					 enum dma_data_direction dir,
-					 struct dma_attrs *attrs)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sgl, sg, nelems, i)
-		dmac_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
-				sg->length, dir);
-	swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
-}
-
-static void arm64_swiotlb_sync_single_for_cpu(struct device *dev,
-					      dma_addr_t dev_addr,
-					      size_t size,
-					      enum dma_data_direction dir)
-{
-	dmac_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
-	swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
-}
-
-static void arm64_swiotlb_sync_single_for_device(struct device *dev,
-						 dma_addr_t dev_addr,
-						 size_t size,
-						 enum dma_data_direction dir)
-{
-	swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
-	dmac_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
-}
-
-static void arm64_swiotlb_sync_sg_for_cpu(struct device *dev,
-					  struct scatterlist *sgl, int nelems,
-					  enum dma_data_direction dir)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sgl, sg, nelems, i)
-		dmac_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
-				sg->length, dir);
-	swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
-}
-
-static void arm64_swiotlb_sync_sg_for_device(struct device *dev,
-					     struct scatterlist *sgl,
-					     int nelems,
-					     enum dma_data_direction dir)
-{
-	struct scatterlist *sg;
-	int i;
-
-	swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
-	for_each_sg(sgl, sg, nelems, i)
-		dmac_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
-			      sg->length, dir);
-}
-
 static struct dma_map_ops arm64_swiotlb_dma_ops = {
 	.alloc = arm64_swiotlb_alloc_coherent,
 	.free = arm64_swiotlb_free_coherent,
-	.map_page = arm64_swiotlb_map_page,
-	.unmap_page = arm64_swiotlb_unmap_page,
-	.map_sg = arm64_swiotlb_map_sg_attrs,
-	.unmap_sg = arm64_swiotlb_unmap_sg_attrs,
-	.sync_single_for_cpu = arm64_swiotlb_sync_single_for_cpu,
-	.sync_single_for_device = arm64_swiotlb_sync_single_for_device,
-	.sync_sg_for_cpu = arm64_swiotlb_sync_sg_for_cpu,
-	.sync_sg_for_device = arm64_swiotlb_sync_sg_for_device,
+	.map_page = swiotlb_map_page,
+	.unmap_page = swiotlb_unmap_page,
+	.map_sg = swiotlb_map_sg_attrs,
+	.unmap_sg = swiotlb_unmap_sg_attrs,
+	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
+	.sync_single_for_device = swiotlb_sync_single_for_device,
+	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
+	.sync_sg_for_device = swiotlb_sync_sg_for_device,
 	.dma_supported = swiotlb_dma_supported,
 	.mapping_error = swiotlb_dma_mapping_error,
 };