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, 9 insertions, 8 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7e440d41487a..a8137dcf5a00 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2819,19 +2819,19 @@ static inline void ib_dma_unmap_single(struct ib_device *dev,
 static inline u64 ib_dma_map_single_attrs(struct ib_device *dev,
 					  void *cpu_addr, size_t size,
 					  enum dma_data_direction direction,
-					  struct dma_attrs *attrs)
+					  unsigned long dma_attrs)
 {
 	return dma_map_single_attrs(dev->dma_device, cpu_addr, size,
-				    direction, attrs);
+				    direction, dma_attrs);
 }
 
 static inline void ib_dma_unmap_single_attrs(struct ib_device *dev,
 					     u64 addr, size_t size,
 					     enum dma_data_direction direction,
-					     struct dma_attrs *attrs)
+					     unsigned long dma_attrs)
 {
 	return dma_unmap_single_attrs(dev->dma_device, addr, size,
-				      direction, attrs);
+				      direction, dma_attrs);
 }
 
 /**
@@ -2906,17 +2906,18 @@ static inline void ib_dma_unmap_sg(struct ib_device *dev,
 static inline int ib_dma_map_sg_attrs(struct ib_device *dev,
 				      struct scatterlist *sg, int nents,
 				      enum dma_data_direction direction,
-				      struct dma_attrs *attrs)
+				      unsigned long dma_attrs)
 {
-	return dma_map_sg_attrs(dev->dma_device, sg, nents, direction, attrs);
+	return dma_map_sg_attrs(dev->dma_device, sg, nents, direction,
+				dma_attrs);
 }
 
 static inline void ib_dma_unmap_sg_attrs(struct ib_device *dev,
 					 struct scatterlist *sg, int nents,
 					 enum dma_data_direction direction,
-					 struct dma_attrs *attrs)
+					 unsigned long dma_attrs)
 {
-	dma_unmap_sg_attrs(dev->dma_device, sg, nents, direction, attrs);
+	dma_unmap_sg_attrs(dev->dma_device, sg, nents, direction, dma_attrs);
 }
 /**
  * ib_sg_dma_address - Return the DMA address from a scatter/gather entry