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, 8 insertions, 8 deletions

diff --git a/arch/x86/pci/vmd.c b/arch/x86/pci/vmd.c
index e88b4176260f..b814ca675131 100644
--- a/arch/x86/pci/vmd.c
+++ b/arch/x86/pci/vmd.c
@@ -274,14 +274,14 @@ static struct dma_map_ops *vmd_dma_ops(struct device *dev)
 }
 
 static void *vmd_alloc(struct device *dev, size_t size, dma_addr_t *addr,
-		       gfp_t flag, struct dma_attrs *attrs)
+		       gfp_t flag, unsigned long attrs)
 {
 	return vmd_dma_ops(dev)->alloc(to_vmd_dev(dev), size, addr, flag,
 				       attrs);
 }
 
 static void vmd_free(struct device *dev, size_t size, void *vaddr,
-		     dma_addr_t addr, struct dma_attrs *attrs)
+		     dma_addr_t addr, unsigned long attrs)
 {
 	return vmd_dma_ops(dev)->free(to_vmd_dev(dev), size, vaddr, addr,
 				      attrs);
@@ -289,7 +289,7 @@ static void vmd_free(struct device *dev, size_t size, void *vaddr,
 
 static int vmd_mmap(struct device *dev, struct vm_area_struct *vma,
 		    void *cpu_addr, dma_addr_t addr, size_t size,
-		    struct dma_attrs *attrs)
+		    unsigned long attrs)
 {
 	return vmd_dma_ops(dev)->mmap(to_vmd_dev(dev), vma, cpu_addr, addr,
 				      size, attrs);
@@ -297,7 +297,7 @@ static int vmd_mmap(struct device *dev, struct vm_area_struct *vma,
 
 static int vmd_get_sgtable(struct device *dev, struct sg_table *sgt,
 			   void *cpu_addr, dma_addr_t addr, size_t size,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	return vmd_dma_ops(dev)->get_sgtable(to_vmd_dev(dev), sgt, cpu_addr,
 					     addr, size, attrs);
@@ -306,26 +306,26 @@ static int vmd_get_sgtable(struct device *dev, struct sg_table *sgt,
 static dma_addr_t vmd_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)
 {
 	return vmd_dma_ops(dev)->map_page(to_vmd_dev(dev), page, offset, size,
 					  dir, attrs);
 }
 
 static void vmd_unmap_page(struct device *dev, dma_addr_t addr, size_t size,
-			   enum dma_data_direction dir, struct dma_attrs *attrs)
+			   enum dma_data_direction dir, unsigned long attrs)
 {
 	vmd_dma_ops(dev)->unmap_page(to_vmd_dev(dev), addr, size, dir, attrs);
 }
 
 static int vmd_map_sg(struct device *dev, struct scatterlist *sg, int nents,
-		      enum dma_data_direction dir, struct dma_attrs *attrs)
+		      enum dma_data_direction dir, unsigned long attrs)
 {
 	return vmd_dma_ops(dev)->map_sg(to_vmd_dev(dev), sg, nents, dir, attrs);
 }
 
 static void vmd_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
-			 enum dma_data_direction dir, struct dma_attrs *attrs)
+			 enum dma_data_direction dir, unsigned long attrs)
 {
 	vmd_dma_ops(dev)->unmap_sg(to_vmd_dev(dev), sg, nents, dir, attrs);
 }