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/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 42ec4600b7e4..151b86b6d2e2 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -783,7 +783,7 @@ sba_map_single(struct device *dev, void *addr, size_t size,
 static dma_addr_t
 sba_map_page(struct device *dev, struct page *page, unsigned long offset,
 		size_t size, enum dma_data_direction direction,
-		struct dma_attrs *attrs)
+		unsigned long attrs)
 {
 	return sba_map_single(dev, page_address(page) + offset, size,
 			direction);
@@ -801,7 +801,7 @@ sba_map_page(struct device *dev, struct page *page, unsigned long offset,
  */
 static void
 sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
-		enum dma_data_direction direction, struct dma_attrs *attrs)
+		enum dma_data_direction direction, unsigned long attrs)
 {
 	struct ioc *ioc;
 #if DELAYED_RESOURCE_CNT > 0
@@ -876,7 +876,7 @@ sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
  * See Documentation/DMA-API-HOWTO.txt
  */
 static void *sba_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
-		gfp_t gfp, struct dma_attrs *attrs)
+		gfp_t gfp, unsigned long attrs)
 {
 	void *ret;
 
@@ -908,9 +908,9 @@ static void *sba_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle
  */
 static void
 sba_free(struct device *hwdev, size_t size, void *vaddr,
-		    dma_addr_t dma_handle, struct dma_attrs *attrs)
+		    dma_addr_t dma_handle, unsigned long attrs)
 {
-	sba_unmap_page(hwdev, dma_handle, size, 0, NULL);
+	sba_unmap_page(hwdev, dma_handle, size, 0, 0);
 	free_pages((unsigned long) vaddr, get_order(size));
 }
 
@@ -943,7 +943,7 @@ int dump_run_sg = 0;
  */
 static int
 sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
-	   enum dma_data_direction direction, struct dma_attrs *attrs)
+	   enum dma_data_direction direction, unsigned long attrs)
 {
 	struct ioc *ioc;
 	int coalesced, filled = 0;
@@ -1026,7 +1026,7 @@ sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
  */
 static void 
 sba_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
-	     enum dma_data_direction direction, struct dma_attrs *attrs)
+	     enum dma_data_direction direction, unsigned long attrs)
 {
 	struct ioc *ioc;
 #ifdef ASSERT_PDIR_SANITY
@@ -1051,7 +1051,7 @@ sba_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	while (sg_dma_len(sglist) && nents--) {
 
 		sba_unmap_page(dev, sg_dma_address(sglist), sg_dma_len(sglist),
-				direction, NULL);
+				direction, 0);
 #ifdef SBA_COLLECT_STATS
 		ioc->usg_pages += ((sg_dma_address(sglist) & ~IOVP_MASK) + sg_dma_len(sglist) + IOVP_SIZE - 1) >> PAGE_SHIFT;
 		ioc->usingle_calls--;	/* kluge since call is unmap_sg() */