dma-mapping: use unsigned long for dma_attrs

The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Acked-by: Vineet Gupta <[email protected]>
Acked-by: Robin Murphy <[email protected]>
Acked-by: Hans-Christian Noren Egtvedt <[email protected]>
Acked-by: Mark Salter <[email protected]> [c6x]
Acked-by: Jesper Nilsson <[email protected]> [cris]
Acked-by: Daniel Vetter <[email protected]> [drm]
Reviewed-by: Bart Van Assche <[email protected]>
Acked-by: Joerg Roedel <[email protected]> [iommu]
Acked-by: Fabien Dessenne <[email protected]> [bdisp]
Reviewed-by: Marek Szyprowski <[email protected]> [vb2-core]
Acked-by: David Vrabel <[email protected]> [xen]
Acked-by: Konrad Rzeszutek Wilk <[email protected]> [xen swiotlb]
Acked-by: Joerg Roedel <[email protected]> [iommu]
Acked-by: Richard Kuo <[email protected]> [hexagon]
Acked-by: Geert Uytterhoeven <[email protected]> [m68k]
Acked-by: Gerald Schaefer <[email protected]> [s390]
Acked-by: Bjorn Andersson <[email protected]>
Acked-by: Hans-Christian Noren Egtvedt <[email protected]> [avr32]
Acked-by: Vineet Gupta <[email protected]> [arc]
Acked-by: Robin Murphy <[email protected]> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/iommu/amd_iommu.c

@@ -2375,7 +2375,7 @@ static void __unmap_single(struct dma_ops_domain *dma_dom,
 static dma_addr_t map_page(struct device *dev, struct page *page,
 			   unsigned long offset, size_t size,
 			   enum dma_data_direction dir,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	phys_addr_t paddr = page_to_phys(page) + offset;
 	struct protection_domain *domain;
@@ -2398,7 +2398,7 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
  * The exported unmap_single function for dma_ops.
  */
 static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
-		       enum dma_data_direction dir, struct dma_attrs *attrs)
+		       enum dma_data_direction dir, unsigned long attrs)
 {
 	struct protection_domain *domain;
 	struct dma_ops_domain *dma_dom;
@@ -2444,7 +2444,7 @@ static int sg_num_pages(struct device *dev,
  */
 static int map_sg(struct device *dev, struct scatterlist *sglist,
 		  int nelems, enum dma_data_direction direction,
-		  struct dma_attrs *attrs)
+		  unsigned long attrs)
 {
 	int mapped_pages = 0, npages = 0, prot = 0, i;
 	struct protection_domain *domain;
@@ -2525,7 +2525,7 @@ out_err:
  */
 static void unmap_sg(struct device *dev, struct scatterlist *sglist,
 		     int nelems, enum dma_data_direction dir,
-		     struct dma_attrs *attrs)
+		     unsigned long attrs)
 {
 	struct protection_domain *domain;
 	struct dma_ops_domain *dma_dom;
@@ -2548,7 +2548,7 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
  */
 static void *alloc_coherent(struct device *dev, size_t size,
 			    dma_addr_t *dma_addr, gfp_t flag,
-			    struct dma_attrs *attrs)
+			    unsigned long attrs)
 {
 	u64 dma_mask = dev->coherent_dma_mask;
 	struct protection_domain *domain;
@@ -2604,7 +2604,7 @@ out_free:
  */
 static void free_coherent(struct device *dev, size_t size,
 			  void *virt_addr, dma_addr_t dma_addr,
-			  struct dma_attrs *attrs)
+			  unsigned long attrs)
 {
 	struct protection_domain *domain;
 	struct dma_ops_domain *dma_dom;

drivers/iommu/dma-iommu.c

@@ -286,7 +286,7 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
  *	   or NULL on failure.
  */
 struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
-		struct dma_attrs *attrs, int prot, dma_addr_t *handle,
+		unsigned long attrs, int prot, dma_addr_t *handle,
 		void (*flush_page)(struct device *, const void *, phys_addr_t))
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
@@ -306,7 +306,7 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
 	} else {
 		size = ALIGN(size, min_size);
 	}
-	if (dma_get_attr(DMA_ATTR_ALLOC_SINGLE_PAGES, attrs))
+	if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES)
 		alloc_sizes = min_size;
 
 	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -400,7 +400,7 @@ dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
 }
 
 void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
-		enum dma_data_direction dir, struct dma_attrs *attrs)
+		enum dma_data_direction dir, unsigned long attrs)
 {
 	__iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle);
 }
@@ -560,7 +560,7 @@ out_restore_sg:
 }
 
 void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
-		enum dma_data_direction dir, struct dma_attrs *attrs)
+		enum dma_data_direction dir, unsigned long attrs)
 {
 	/*
 	 * The scatterlist segments are mapped into a single

drivers/iommu/intel-iommu.c

@@ -3552,7 +3552,7 @@ error:
 static dma_addr_t intel_map_page(struct device *dev, struct page *page,
 				 unsigned long offset, size_t size,
 				 enum dma_data_direction dir,
-				 struct dma_attrs *attrs)
+				 unsigned long attrs)
 {
 	return __intel_map_single(dev, page_to_phys(page) + offset, size,
 				  dir, *dev->dma_mask);
@@ -3711,14 +3711,14 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
 
 static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
 			     size_t size, enum dma_data_direction dir,
-			     struct dma_attrs *attrs)
+			     unsigned long attrs)
 {
 	intel_unmap(dev, dev_addr, size);
 }
 
 static void *intel_alloc_coherent(struct device *dev, size_t size,
 				  dma_addr_t *dma_handle, gfp_t flags,
-				  struct dma_attrs *attrs)
+				  unsigned long attrs)
 {
 	struct page *page = NULL;
 	int order;
@@ -3764,7 +3764,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
 }
 
 static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
-				dma_addr_t dma_handle, struct dma_attrs *attrs)
+				dma_addr_t dma_handle, unsigned long attrs)
 {
 	int order;
 	struct page *page = virt_to_page(vaddr);
@@ -3779,7 +3779,7 @@ static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
 
 static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
 			   int nelems, enum dma_data_direction dir,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	dma_addr_t startaddr = sg_dma_address(sglist) & PAGE_MASK;
 	unsigned long nrpages = 0;
@@ -3808,7 +3808,7 @@ static int intel_nontranslate_map_sg(struct device *hddev,
 }
 
 static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nelems,
-			enum dma_data_direction dir, struct dma_attrs *attrs)
+			enum dma_data_direction dir, unsigned long attrs)
 {
 	int i;
 	struct dmar_domain *domain;