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]>

arch/frv/mb93090-mb00/pci-dma-nommu.c

@@ -35,7 +35,7 @@ static DEFINE_SPINLOCK(dma_alloc_lock);
 static LIST_HEAD(dma_alloc_list);
 
 static void *frv_dma_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
-		gfp_t gfp, struct dma_attrs *attrs)
+		gfp_t gfp, unsigned long attrs)
 {
 	struct dma_alloc_record *new;
 	struct list_head *this = &dma_alloc_list;
@@ -86,7 +86,7 @@ static void *frv_dma_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_ha
 }
 
 static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, struct dma_attrs *attrs)
+		dma_addr_t dma_handle, unsigned long attrs)
 {
 	struct dma_alloc_record *rec;
 	unsigned long flags;
@@ -107,7 +107,7 @@ static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
 
 static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 		int nents, enum dma_data_direction direction,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	int i;
 	struct scatterlist *sg;
@@ -124,7 +124,7 @@ static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
 		unsigned long offset, size_t size,
-		enum dma_data_direction direction, struct dma_attrs *attrs)
+		enum dma_data_direction direction, unsigned long attrs)
 {
 	BUG_ON(direction == DMA_NONE);
 	flush_dcache_page(page);

arch/frv/mb93090-mb00/pci-dma.c

@@ -19,8 +19,7 @@
 #include <asm/io.h>
 
 static void *frv_dma_alloc(struct device *hwdev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp,
-		struct dma_attrs *attrs)
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	void *ret;
 
@@ -32,14 +31,14 @@ static void *frv_dma_alloc(struct device *hwdev, size_t size,
 }
 
 static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, struct dma_attrs *attrs)
+		dma_addr_t dma_handle, unsigned long attrs)
 {
 	consistent_free(vaddr);
 }
 
 static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 		int nents, enum dma_data_direction direction,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	unsigned long dampr2;
 	void *vaddr;
@@ -69,7 +68,7 @@ static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
 		unsigned long offset, size_t size,
-		enum dma_data_direction direction, struct dma_attrs *attrs)
+		enum dma_data_direction direction, unsigned long attrs)
 {
 	flush_dcache_page(page);
 	return (dma_addr_t) page_to_phys(page) + offset;