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]>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index c5f9a9e3d1f3..d062f08f5020 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -98,11 +98,11 @@ static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
 
 void __xen_dma_map_page(struct device *hwdev, struct page *page,
 	     dma_addr_t dev_addr, unsigned long offset, size_t size,
-	     enum dma_data_direction dir, struct dma_attrs *attrs)
+	     enum dma_data_direction dir, unsigned long attrs)
 {
 	if (is_device_dma_coherent(hwdev))
 		return;
-	if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 		return;
 
 	__xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir);
@@ -110,12 +110,12 @@ void __xen_dma_map_page(struct device *hwdev, struct page *page,
 
 void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 
 {
 	if (is_device_dma_coherent(hwdev))
 		return;
-	if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 		return;
 
 	__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);