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>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 7399782c0998..87e6035c9e81 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -294,7 +294,7 @@ error:
 void *
 xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			   dma_addr_t *dma_handle, gfp_t flags,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	void *ret;
 	int order = get_order(size);
@@ -346,7 +346,7 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent);
 
 void
 xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
-			  dma_addr_t dev_addr, struct dma_attrs *attrs)
+			  dma_addr_t dev_addr, unsigned long attrs)
 {
 	int order = get_order(size);
 	phys_addr_t phys;
@@ -378,7 +378,7 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent);
 dma_addr_t xen_swiotlb_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 map, phys = page_to_phys(page) + offset;
 	dma_addr_t dev_addr = xen_phys_to_bus(phys);
@@ -434,7 +434,7 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
  */
 static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
 			     size_t size, enum dma_data_direction dir,
-				 struct dma_attrs *attrs)
+			     unsigned long attrs)
 {
 	phys_addr_t paddr = xen_bus_to_phys(dev_addr);
 
@@ -462,7 +462,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
 
 void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
 			    size_t size, enum dma_data_direction dir,
-			    struct dma_attrs *attrs)
+			    unsigned long attrs)
 {
 	xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
 }
@@ -538,7 +538,7 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device);
 int
 xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 			 int nelems, enum dma_data_direction dir,
-			 struct dma_attrs *attrs)
+			 unsigned long attrs)
 {
 	struct scatterlist *sg;
 	int i;
@@ -599,7 +599,7 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs);
 void
 xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 			   int nelems, enum dma_data_direction dir,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	struct scatterlist *sg;
 	int i;