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, 6 insertions, 6 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index afbaa2c69a59..ebb5bf3ddbd9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3552,7 +3552,7 @@ error:
 static dma_addr_t intel_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 __intel_map_single(dev, page_to_phys(page) + offset, size,
 				  dir, *dev->dma_mask);
@@ -3711,14 +3711,14 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
 
 static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
 			     size_t size, enum dma_data_direction dir,
-			     struct dma_attrs *attrs)
+			     unsigned long attrs)
 {
 	intel_unmap(dev, dev_addr, size);
 }
 
 static void *intel_alloc_coherent(struct device *dev, size_t size,
 				  dma_addr_t *dma_handle, gfp_t flags,
-				  struct dma_attrs *attrs)
+				  unsigned long attrs)
 {
 	struct page *page = NULL;
 	int order;
@@ -3764,7 +3764,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
 }
 
 static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
-				dma_addr_t dma_handle, struct dma_attrs *attrs)
+				dma_addr_t dma_handle, unsigned long attrs)
 {
 	int order;
 	struct page *page = virt_to_page(vaddr);
@@ -3779,7 +3779,7 @@ static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
 
 static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
 			   int nelems, enum dma_data_direction dir,
-			   struct dma_attrs *attrs)
+			   unsigned long attrs)
 {
 	dma_addr_t startaddr = sg_dma_address(sglist) & PAGE_MASK;
 	unsigned long nrpages = 0;
@@ -3808,7 +3808,7 @@ static int intel_nontranslate_map_sg(struct device *hddev,
 }
 
 static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nelems,
-			enum dma_data_direction dir, struct dma_attrs *attrs)
+			enum dma_data_direction dir, unsigned long attrs)
 {
 	int i;
 	struct dmar_domain *domain;