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/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/sparc/kernel/iommu.c

@@ -196,7 +196,7 @@ static inline void iommu_free_ctx(struct iommu *iommu, int ctx)
 
 static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
 				   dma_addr_t *dma_addrp, gfp_t gfp,
-				   struct dma_attrs *attrs)
+				   unsigned long attrs)
 {
 	unsigned long order, first_page;
 	struct iommu *iommu;
@@ -245,7 +245,7 @@ static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
 
 static void dma_4u_free_coherent(struct device *dev, size_t size,
 				 void *cpu, dma_addr_t dvma,
-				 struct dma_attrs *attrs)
+				 unsigned long attrs)
 {
 	struct iommu *iommu;
 	unsigned long order, npages;
@@ -263,7 +263,7 @@ static void dma_4u_free_coherent(struct device *dev, size_t size,
 static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
 				  unsigned long offset, size_t sz,
 				  enum dma_data_direction direction,
-				  struct dma_attrs *attrs)
+				  unsigned long attrs)
 {
 	struct iommu *iommu;
 	struct strbuf *strbuf;
@@ -385,7 +385,7 @@ do_flush_sync:
 
 static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 			      size_t sz, enum dma_data_direction direction,
-			      struct dma_attrs *attrs)
+			      unsigned long attrs)
 {
 	struct iommu *iommu;
 	struct strbuf *strbuf;
@@ -431,7 +431,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 
 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
 			 int nelems, enum dma_data_direction direction,
-			 struct dma_attrs *attrs)
+			 unsigned long attrs)
 {
 	struct scatterlist *s, *outs, *segstart;
 	unsigned long flags, handle, prot, ctx;
@@ -607,7 +607,7 @@ static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
 
 static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 			    int nelems, enum dma_data_direction direction,
-			    struct dma_attrs *attrs)
+			    unsigned long attrs)
 {
 	unsigned long flags, ctx;
 	struct scatterlist *sg;